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Cai Z, Cao H, Sheng H, Hu X, Sun Z, Zhao Q, Gao J, Ideta SI, Shimada K, Huang J, Cheng P, Chen L, Yao Y, Meng S, Wu K, Wang Z, Feng B. Evidence for Two-Dimensional Weyl Fermions in Air-Stable Monolayer PtTe 1.75. NANO LETTERS 2024. [PMID: 39092903 DOI: 10.1021/acs.nanolett.4c02580] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 08/04/2024]
Abstract
The Weyl semimetals represent a distinct category of topological materials wherein the low-energy excitations appear as the long-sought Weyl Fermions. Exotic transport and optical properties are expected because of the chiral anomaly and linear energy-momentum dispersion. While three-dimensional Weyl semimetals have been successfully realized, the quest for their two-dimensional (2D) counterparts is ongoing. Here, we report the realization of 2D Weyl Fermions in monolayer PtTe1.75, which has strong spin-orbit coupling and lacks inversion symmetry, by combined angle-resolved photoemission spectroscopy, scanning tunneling microscopy, second harmonic generation, X-ray photoelectron spectroscopy measurements, and first-principles calculations. The giant Rashba splitting and band inversion lead to the emergence of three pairs of critical Weyl cones. Moreover, monolayer PtTe1.75 exhibits excellent chemical stability in ambient conditions, which is critical for future device applications. The discovery of 2D Weyl Fermions in monolayer PtTe1.75 opens up new possibilities for designing and fabricating novel spintronic devices.
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Affiliation(s)
- Zhihao Cai
- Institute of Physics, Chinese Academy of Sciences, Beijing 100190, China
- School of Physical Sciences, University of Chinese Academy of Sciences, Beijing 100049, China
| | - Haijun Cao
- Institute of Physics, Chinese Academy of Sciences, Beijing 100190, China
- School of Physical Sciences, University of Chinese Academy of Sciences, Beijing 100049, China
| | - Haohao Sheng
- Institute of Physics, Chinese Academy of Sciences, Beijing 100190, China
- School of Physical Sciences, University of Chinese Academy of Sciences, Beijing 100049, China
| | - Xuegao Hu
- Institute of Physics, Chinese Academy of Sciences, Beijing 100190, China
- School of Physical Sciences, University of Chinese Academy of Sciences, Beijing 100049, China
| | - Zhenyu Sun
- Institute of Physics, Chinese Academy of Sciences, Beijing 100190, China
- School of Physical Sciences, University of Chinese Academy of Sciences, Beijing 100049, China
| | - Qiaoxiao Zhao
- Institute of Physics, Chinese Academy of Sciences, Beijing 100190, China
- School of Physical Sciences, University of Chinese Academy of Sciences, Beijing 100049, China
| | - Jisong Gao
- Institute of Physics, Chinese Academy of Sciences, Beijing 100190, China
- School of Physical Sciences, University of Chinese Academy of Sciences, Beijing 100049, China
| | - Shin-Ichiro Ideta
- Hiroshima Synchrotron Radiation Center, Hiroshima University, Higashi-Hiroshima 739-0046, Japan
| | - Kenya Shimada
- Hiroshima Synchrotron Radiation Center, Hiroshima University, Higashi-Hiroshima 739-0046, Japan
| | - Jiawei Huang
- Songshan Lake Materials Laboratory, Dongguan, Guangdong 523808, China
| | - Peng Cheng
- Institute of Physics, Chinese Academy of Sciences, Beijing 100190, China
- School of Physical Sciences, University of Chinese Academy of Sciences, Beijing 100049, China
| | - Lan Chen
- Institute of Physics, Chinese Academy of Sciences, Beijing 100190, China
- School of Physical Sciences, University of Chinese Academy of Sciences, Beijing 100049, China
- Songshan Lake Materials Laboratory, Dongguan, Guangdong 523808, China
| | - Yugui Yao
- Centre for Quantum Physics, Key Laboratory of Advanced Optoelectronic Quantum Architecture and Measurement (MOE), School of Physics and Beijing Key Lab of Nanophotonics Ultrafine Optoelectronic Systems, School of Physics, Beijing Institute of Technology, Beijing 100081, China
| | - Sheng Meng
- Institute of Physics, Chinese Academy of Sciences, Beijing 100190, China
- School of Physical Sciences, University of Chinese Academy of Sciences, Beijing 100049, China
- Songshan Lake Materials Laboratory, Dongguan, Guangdong 523808, China
- Interdisciplinary Institute of Light-Element Quantum Materials and Research Center for Light-Element Advanced Materials, Peking University, Beijing 100871, China
| | - Kehui Wu
- Institute of Physics, Chinese Academy of Sciences, Beijing 100190, China
- School of Physical Sciences, University of Chinese Academy of Sciences, Beijing 100049, China
- Songshan Lake Materials Laboratory, Dongguan, Guangdong 523808, China
- Interdisciplinary Institute of Light-Element Quantum Materials and Research Center for Light-Element Advanced Materials, Peking University, Beijing 100871, China
| | - Zhijun Wang
- Institute of Physics, Chinese Academy of Sciences, Beijing 100190, China
- School of Physical Sciences, University of Chinese Academy of Sciences, Beijing 100049, China
| | - Baojie Feng
- Institute of Physics, Chinese Academy of Sciences, Beijing 100190, China
- School of Physical Sciences, University of Chinese Academy of Sciences, Beijing 100049, China
- Songshan Lake Materials Laboratory, Dongguan, Guangdong 523808, China
- Interdisciplinary Institute of Light-Element Quantum Materials and Research Center for Light-Element Advanced Materials, Peking University, Beijing 100871, China
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2
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Datta S, Ali K, Verma R, Singh B, Dash SP, Thamizhavel A, Maiti K. Anomalies in the Dirac bands in the proximity of correlated electrons. NANOSCALE 2024; 16:13861-13866. [PMID: 38975688 DOI: 10.1039/d4nr01535e] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 07/09/2024]
Abstract
Dirac fermions, particles with zero rest mass, are observed in topological materials and are believed to play a key role in the exotic phenomena in fundamental science and the advancement of quantum technology. Most of the topological systems studied so far are weakly correlated systems and the study of their properties in the presence of electron correlation is an interesting emerging area of research, where the electron correlation is expected to enhance the effective mass of the particles. Here, we studied the properties of Dirac bands in a non-symmorphic layered Kondo lattice system, CeAgSb2, employing high-resolution angle-resolved photoemission spectroscopy and first-principles calculations. In addition to the Dirac cones due to non-symmorphic symmetry, this material hosts Dirac fermions in the squarenet layer in the proximity of a strongly correlated Ce layer exhibiting Kondo behavior. Experimental results reveal crossings of the highly dispersive linear bands at the Brillouin zone boundary due to non-symmorphic symmetry. In addition, there are anisotropic Dirac cones constituted by the squarenet Sb 5p states forming a diamond-shaped nodal line. These Dirac bands are linear in a wide energy range with an unusually high slope. Interestingly, near the local Ce 4f bands, these bands exhibit a change in the slope akin to the formation of a 'kink' observed in other materials due to electron-phonon coupling. The emergence of such exotic properties in proximity to strongly correlated electronic states has significant implications in the study of complex quantum materials including unconventional superconductors.
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Affiliation(s)
- Sawani Datta
- Department of Condensed Matter Physics and Materials Science, Tata Institute of Fundamental Research, Homi Bhabha Road, Colaba, Mumbai-400005, India.
| | - Khadiza Ali
- Department of Microtechnology and Nanoscience, Chalmers University of Technology, Göteborg, 41296, Sweden
| | - Rahul Verma
- Department of Condensed Matter Physics and Materials Science, Tata Institute of Fundamental Research, Homi Bhabha Road, Colaba, Mumbai-400005, India.
| | - Bahadur Singh
- Department of Condensed Matter Physics and Materials Science, Tata Institute of Fundamental Research, Homi Bhabha Road, Colaba, Mumbai-400005, India.
| | - Saroj P Dash
- Department of Microtechnology and Nanoscience, Chalmers University of Technology, Göteborg, 41296, Sweden
| | - A Thamizhavel
- Department of Condensed Matter Physics and Materials Science, Tata Institute of Fundamental Research, Homi Bhabha Road, Colaba, Mumbai-400005, India.
| | - Kalobaran Maiti
- Department of Condensed Matter Physics and Materials Science, Tata Institute of Fundamental Research, Homi Bhabha Road, Colaba, Mumbai-400005, India.
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3
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Wang H, Kaneko R, Ueda K, Zhang Y, Baron AQR, Ishikawa D, Wehinger B, Dagotto E, Tokura Y, Arima TH, Gao S. Phonon excitations in Eu 2Ir 2O 7probed by inelastic x-ray scattering. JOURNAL OF PHYSICS. CONDENSED MATTER : AN INSTITUTE OF PHYSICS JOURNAL 2024; 36:425705. [PMID: 38976987 DOI: 10.1088/1361-648x/ad604d] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/12/2024] [Accepted: 07/08/2024] [Indexed: 07/10/2024]
Abstract
The study of phonon dynamics and its interplay with magnetic ordering is crucial for understanding the unique quantum phases in the pyrochlore iridates. Here, through inelastic x-ray scattering on a single crystal sample of the pyrochlore iridate Eu2Ir2O7, we map out the phonon excitation spectra in Eu2Ir2O7and compare them with the theoretical phonon spectra calculated using the density functional theory. Possible phonon renormalization across the magnetic long-range order transition is observed in our experiments, which is consistent with the results of the previous Raman scattering experiments.
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Affiliation(s)
- Han Wang
- Department of Physics, University of Science and Technology of China, Hefei 230026, People's Republic of China
| | - Ryoma Kaneko
- RIKEN Center for Emergent Matter Science, Wako 351-0198, Japan
- Department of Applied Physics, University of Tokyo, Tokyo 113-8656, Japan
| | - Kentaro Ueda
- RIKEN Center for Emergent Matter Science, Wako 351-0198, Japan
- Department of Applied Physics, University of Tokyo, Tokyo 113-8656, Japan
| | - Yang Zhang
- Department of Physics and Astronomy, University of Tennessee, Knoxville, TN 37996, United States of America
| | - Alfred Q R Baron
- Materials Dynamics Laboratory, RIKEN SPring-8 Center, Sayo 679-5198, Japan
| | - Daisuke Ishikawa
- Materials Dynamics Laboratory, RIKEN SPring-8 Center, Sayo 679-5198, Japan
| | - Björn Wehinger
- European Synchrotron Radiation Facility, 71, Avenue des Martyrs, Grenoble 38000, France
| | - Elbio Dagotto
- Department of Physics and Astronomy, University of Tennessee, Knoxville, TN 37996, United States of America
- Materials Science and Technology Division, Oak Ridge National Laboratory, TN 37831, United States of America
| | - Yoshinori Tokura
- RIKEN Center for Emergent Matter Science, Wako 351-0198, Japan
- Department of Applied Physics, University of Tokyo, Tokyo 113-8656, Japan
- Tokyo College, University of Tokyo, Tokyo 113-8656, Japan
| | - Taka-Hisa Arima
- RIKEN Center for Emergent Matter Science, Wako 351-0198, Japan
- Department of Advanced Materials Science, University of Tokyo, Kashiwa 277-8561, Japan
| | - Shang Gao
- Department of Physics, University of Science and Technology of China, Hefei 230026, People's Republic of China
- RIKEN Center for Emergent Matter Science, Wako 351-0198, Japan
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4
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Johansson A. Theory of spin and orbital Edelstein effects. JOURNAL OF PHYSICS. CONDENSED MATTER : AN INSTITUTE OF PHYSICS JOURNAL 2024; 36:423002. [PMID: 38955339 DOI: 10.1088/1361-648x/ad5e2b] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 02/25/2024] [Accepted: 07/01/2024] [Indexed: 07/04/2024]
Abstract
In systems with broken spatial inversion symmetry, such as surfaces, interfaces, or bulk systems lacking an inversion center, the application of a charge current can generate finite spin and orbital densities associated with a nonequilibrium magnetization, which is known as spin and orbital Edelstein effect (SEE and OEE), respectively. Early reports on this current-induced magnetization focus on two-dimensional Rashba systems, in which an in-plane nonequilibrium spin density is generated perpendicular to the applied charge current. However, until today, a large variety of materials have been theoretically predicted and experimentally demonstrated to exhibit a sizeable Edelstein effect, which comprises contributions from the spin as well as the orbital degrees of freedom, and whose associated magnetization may be out of plane, nonorthogonal, and even parallel to the applied charge current, depending on the system's particular symmetries. In this review, we give an overview on the most commonly used theoretical approaches for the discussion and prediction of the SEE and OEE. Further, we introduce a selection of the most intensely discussed materials exhibiting a finite Edelstein effect, and give a brief summary of common experimental techniques.
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Affiliation(s)
- Annika Johansson
- Max Planck Institute of Microstructure Physics, Weinberg 2, 06120 Halle (Saale), Germany
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5
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Lu Q, Reddy PVS, Jeon H, Mazza AR, Brahlek M, Wu W, Yang SA, Cook J, Conner C, Zhang X, Chakraborty A, Yao YT, Tien HJ, Tseng CH, Yang PY, Lien SW, Lin H, Chiang TC, Vignale G, Li AP, Chang TR, Moore RG, Bian G. Realization of a two-dimensional Weyl semimetal and topological Fermi strings. Nat Commun 2024; 15:6001. [PMID: 39019865 PMCID: PMC11255256 DOI: 10.1038/s41467-024-50329-6] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/26/2024] [Accepted: 07/05/2024] [Indexed: 07/19/2024] Open
Abstract
A two-dimensional (2D) Weyl semimetal, akin to a spinful variant of graphene, represents a topological matter characterized by Weyl fermion-like quasiparticles in low dimensions. The spinful linear band structure in two dimensions gives rise to distinctive topological properties, accompanied by the emergence of Fermi string edge states. We report the experimental realization of a 2D Weyl semimetal, bismuthene monolayer grown on SnS(Se) substrates. Using spin and angle-resolved photoemission and scanning tunneling spectroscopies, we directly observe spin-polarized Weyl cones, Weyl nodes, and Fermi strings, providing consistent evidence of their inherent topological characteristics. Our work opens the door for the experimental study of Weyl fermions in low-dimensional materials.
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Affiliation(s)
- Qiangsheng Lu
- Department of Physics and Astronomy, University of Missouri, Columbia, MO, 65211, USA
- Materials Science and Technology Division, Oak Ridge National Laboratory, Oak Ridge, TN, 37831, USA
| | | | - Hoyeon Jeon
- Center for Nanophase Materials Sciences, Oak Ridge National Laboratory, Oak Ridge, TN, 37831, USA
| | - Alessandro R Mazza
- Materials Science and Technology Division, Oak Ridge National Laboratory, Oak Ridge, TN, 37831, USA
- Materials Science and Technology Division, Los Alamos National Laboratory, Los Alamos, NM, 87545, USA
| | - Matthew Brahlek
- Materials Science and Technology Division, Oak Ridge National Laboratory, Oak Ridge, TN, 37831, USA
| | - Weikang Wu
- Research Laboratory for Quantum Materials, Singapore University of Technology and Design, Singapore, 487372, Singapore
| | - Shengyuan A Yang
- Research Laboratory for Quantum Materials, Singapore University of Technology and Design, Singapore, 487372, Singapore
| | - Jacob Cook
- Department of Physics and Astronomy, University of Missouri, Columbia, MO, 65211, USA
| | - Clayton Conner
- Department of Physics and Astronomy, University of Missouri, Columbia, MO, 65211, USA
| | - Xiaoqian Zhang
- Department of Physics and Astronomy, University of Missouri, Columbia, MO, 65211, USA
| | - Amarnath Chakraborty
- Department of Physics and Astronomy, University of Missouri, Columbia, MO, 65211, USA
| | - Yueh-Ting Yao
- Department of Physics, National Cheng Kung University, Tainan, 701, Taiwan
| | - Hung-Ju Tien
- Department of Physics, National Cheng Kung University, Tainan, 701, Taiwan
| | - Chun-Han Tseng
- Department of Physics, National Cheng Kung University, Tainan, 701, Taiwan
| | - Po-Yuan Yang
- Department of Physics, National Cheng Kung University, Tainan, 701, Taiwan
| | - Shang-Wei Lien
- Department of Physics, National Cheng Kung University, Tainan, 701, Taiwan
| | - Hsin Lin
- Institute of Physics, Academia Sinica, Taipei, 11529, Taiwan
| | - Tai-Chang Chiang
- Department of Physics, University of Illinois at Urbana-Champaign, 1110 West Green Street, Urbana, IL, 61801-3080, USA
- Frederick Seitz Materials Research Laboratory, University of Illinois at Urbana-Champaign, 104 South Goodwin Avenue, Urbana, IL, 61801-2902, USA
| | - Giovanni Vignale
- Department of Physics and Astronomy, University of Missouri, Columbia, MO, 65211, USA
| | - An-Ping Li
- Center for Nanophase Materials Sciences, Oak Ridge National Laboratory, Oak Ridge, TN, 37831, USA.
| | - Tay-Rong Chang
- Department of Physics, National Cheng Kung University, Tainan, 701, Taiwan.
- Center for Quantum Frontiers of Research and Technology (QFort), Tainan, 70101, Taiwan.
- Physics Division, National Center for Theoretical Sciences, Taipei, 10617, Taiwan.
| | - Rob G Moore
- Materials Science and Technology Division, Oak Ridge National Laboratory, Oak Ridge, TN, 37831, USA.
| | - Guang Bian
- Department of Physics and Astronomy, University of Missouri, Columbia, MO, 65211, USA.
- MU Materials Science & Engineering Institute, University of Missouri, Columbia, MO, 65211, USA.
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6
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Ma J, Meng X, Zhang B, Wang Y, Mou Y, Lin W, Dai Y, Chen L, Wang H, Wu H, Gu J, Wang J, Du Y, Liu C, Shi W, Yang Z, Tian B, Miao L, Zhou P, Duan CG, Xu C, Yuan X, Zhang C. Memristive switching in the surface of a charge-density-wave topological semimetal. Sci Bull (Beijing) 2024; 69:2042-2049. [PMID: 38824120 DOI: 10.1016/j.scib.2024.05.010] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/11/2023] [Revised: 04/12/2024] [Accepted: 05/13/2024] [Indexed: 06/03/2024]
Abstract
Owing to the outstanding properties provided by nontrivial band topology, topological phases of matter are considered as a promising platform towards low-dissipation electronics, efficient spin-charge conversion, and topological quantum computation. Achieving ferroelectricity in topological materials enables the non-volatile control of the quantum states, which could greatly facilitate topological electronic research. However, ferroelectricity is generally incompatible with systems featuring metallicity due to the screening effect of free carriers. In this study, we report the observation of memristive switching based on the ferroelectric surface state of a topological semimetal (TaSe4)2I. We find that the surface state of (TaSe4)2I presents out-of-plane ferroelectric polarization due to surface reconstruction. With the combination of ferroelectric surface and charge-density-wave-gapped bulk states, an electric-switchable barrier height can be achieved in (TaSe4)2I-metal contact. By employing a multi-terminal-grounding design, we manage to construct a prototype ferroelectric memristor based on (TaSe4)2I with on/off ratio up to 103, endurance over 103 cycles, and good retention characteristics. The origin of the ferroelectric surface state is further investigated by first-principles calculations, which reveal an interplay between ferroelectricity and band topology. The emergence of ferroelectricity in (TaSe4)2I not only demonstrates it as a rare but essential case of ferroelectric topological materials, but also opens new routes towards the implementation of topological materials in functional electronic devices.
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Affiliation(s)
- Jianwen Ma
- State Key Laboratory of Surface Physics and Institute for Nanoelectronic Devices and Quantum Computing, Fudan University, Shanghai 200433, China
| | - Xianghao Meng
- State Key Laboratory of Precision Spectroscopy, East China Normal University, Shanghai 200241, China
| | - Binhua Zhang
- Key Laboratory of Computational Physical Sciences (Ministry of Education), Institute of Computational Physical Sciences, State Key Laboratory of Surface Physics, Department of Physics, Fudan University, Shanghai 200433, China; Shanghai Qi Zhi Institute, Shanghai 200030, China
| | - Yuxiang Wang
- State Key Laboratory of Surface Physics and Institute for Nanoelectronic Devices and Quantum Computing, Fudan University, Shanghai 200433, China
| | - Yicheng Mou
- State Key Laboratory of Surface Physics and Institute for Nanoelectronic Devices and Quantum Computing, Fudan University, Shanghai 200433, China
| | - Wenting Lin
- School of Physics, Southeast University, Nanjing 211189, China
| | - Yannan Dai
- Key Laboratory of Polar Materials and Devices (Ministry of Education), Department of Electronics, East China Normal University, Shanghai 200241, China; Shanghai Center of Brain-inspired Intelligent Materials and Devices, East China Normal University, Shanghai 200241, China
| | - Luqiu Chen
- Key Laboratory of Polar Materials and Devices (Ministry of Education), Department of Electronics, East China Normal University, Shanghai 200241, China; Shanghai Center of Brain-inspired Intelligent Materials and Devices, East China Normal University, Shanghai 200241, China
| | - Haonan Wang
- Key Laboratory of Polar Materials and Devices (Ministry of Education), Department of Electronics, East China Normal University, Shanghai 200241, China
| | - Haoqi Wu
- State Key Laboratory of ASIC and System, School of Microelectronics, Fudan University, Shanghai 200433, China
| | - Jiaming Gu
- State Key Laboratory of Surface Physics and Institute for Nanoelectronic Devices and Quantum Computing, Fudan University, Shanghai 200433, China
| | - Jiayu Wang
- State Key Laboratory of Surface Physics and Institute for Nanoelectronic Devices and Quantum Computing, Fudan University, Shanghai 200433, China
| | - Yuhan Du
- State Key Laboratory of Precision Spectroscopy, East China Normal University, Shanghai 200241, China
| | - Chunsen Liu
- Frontier Institute of Chip and System, Fudan University, Shanghai 200433, China
| | - Wu Shi
- State Key Laboratory of Surface Physics and Institute for Nanoelectronic Devices and Quantum Computing, Fudan University, Shanghai 200433, China; Zhangjiang Fudan International Innovation Center, Fudan University, Shanghai 201210, China
| | - Zhenzhong Yang
- Key Laboratory of Polar Materials and Devices (Ministry of Education), Department of Electronics, East China Normal University, Shanghai 200241, China
| | - Bobo Tian
- Key Laboratory of Polar Materials and Devices (Ministry of Education), Department of Electronics, East China Normal University, Shanghai 200241, China; Shanghai Center of Brain-inspired Intelligent Materials and Devices, East China Normal University, Shanghai 200241, China
| | - Lin Miao
- School of Physics, Southeast University, Nanjing 211189, China
| | - Peng Zhou
- State Key Laboratory of ASIC and System, School of Microelectronics, Fudan University, Shanghai 200433, China; Frontier Institute of Chip and System, Fudan University, Shanghai 200433, China
| | - Chun-Gang Duan
- Key Laboratory of Polar Materials and Devices (Ministry of Education), Department of Electronics, East China Normal University, Shanghai 200241, China; Shanghai Center of Brain-inspired Intelligent Materials and Devices, East China Normal University, Shanghai 200241, China
| | - Changsong Xu
- Key Laboratory of Computational Physical Sciences (Ministry of Education), Institute of Computational Physical Sciences, State Key Laboratory of Surface Physics, Department of Physics, Fudan University, Shanghai 200433, China; Shanghai Qi Zhi Institute, Shanghai 200030, China.
| | - Xiang Yuan
- State Key Laboratory of Precision Spectroscopy, East China Normal University, Shanghai 200241, China; Shanghai Center of Brain-inspired Intelligent Materials and Devices, East China Normal University, Shanghai 200241, China; School of Physics and Electronic Science, East China Normal University, Shanghai 200241, China.
| | - Cheng Zhang
- State Key Laboratory of Surface Physics and Institute for Nanoelectronic Devices and Quantum Computing, Fudan University, Shanghai 200433, China; Zhangjiang Fudan International Innovation Center, Fudan University, Shanghai 201210, China.
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7
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Yu XJ, Yang S, Lin HQ, Jian SK. Universal Entanglement Spectrum in One-Dimensional Gapless Symmetry Protected Topological States. PHYSICAL REVIEW LETTERS 2024; 133:026601. [PMID: 39073949 DOI: 10.1103/physrevlett.133.026601] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 02/13/2024] [Revised: 05/16/2024] [Accepted: 06/11/2024] [Indexed: 07/31/2024]
Abstract
Quantum entanglement marks a definitive feature of topological states. However, the entanglement spectrum remains insufficiently explored for topological states without a bulk energy gap. Using a combination of field theory and numerical techniques, we accurately calculate and analyze the entanglement spectrum of gapless symmetry protected topological states in one dimension. We highlight that the universal entanglement spectrum not only encodes the nontrivial edge degeneracy, generalizing the Li-Haldane conjecture to gapless topological states, but also contains the operator content of the underlying boundary conformal field theory. This implies that the bulk wave function can act as a fingerprint of both quantum criticality and topology in gapless symmetry protected topological states. We also identify a symmetry enriched conformal boundary condition that goes beyond the conventional conformal boundary condition.
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Affiliation(s)
- Xue-Jia Yu
- Department of Physics, Fuzhou University, Fuzhou 350116, Fujian, China
- Fujian Key Laboratory of Quantum Information and Quantum Optics, College of Physics and Information Engineering, Fuzhou University, Fuzhou, Fujian 350108, China
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8
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Sarisaman M, Tasdemir S, Rostamzadeh S. Topological behavior of spectral singularities in topological Weyl semimetals. JOURNAL OF PHYSICS. CONDENSED MATTER : AN INSTITUTE OF PHYSICS JOURNAL 2024; 36:405603. [PMID: 38941987 DOI: 10.1088/1361-648x/ad5d41] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/27/2024] [Accepted: 06/28/2024] [Indexed: 06/30/2024]
Abstract
In this study, we examine the topological character of spectral singularities by using transverse magnetic (TM) mode configuration in a Topological Weyl Semimetal (TWSM). TM mode configuration restrains the effect of Kerr/Faraday rotations and therefore does not allow an extra degree of freedom to occur. We find out that surface currents arise due to topological terms on the surface of TWSM slab where no Fermi arcs are localized. We also investigate the contribution of the Θ-term, which is the origin of axions in topological materials, and especially theb-term, to the topological properties. As a result of our study, we clearly reveal the topological character ofb-term for the first time and we demonstrate the Weyl degeneracy situation in an obvious manner. Our system produces circular currents in the plane of propagation, maintaining a cyclotron shape motion. The presence ofb-term causes the induced current to be topologically protected. Our findings verify that topological properties of TWSM containing two opposite chirality Weyl fermions are robust against external influences. With the findings of our study, the appropriate conditions for the construction of a topological laser and the values that the system parameters can take have been demonstrated.
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Affiliation(s)
- Mustafa Sarisaman
- Department of Physics, Istanbul University, 34134 Vezneciler, Istanbul, Turkey
| | - Sevval Tasdemir
- Department of Physics, Kocaeli University, 41380 Kocaeli, Turkey
| | - Saber Rostamzadeh
- Department of Physics, Istanbul University, 34134 Vezneciler, Istanbul, Turkey
- Université de Bordeaux, CNRS LOMA UMR 5798, Talence F-33405, France
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9
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Lim CY, Kim MS, Lim DC, Kim S, Lee Y, Cha J, Lee G, Song SY, Thapa D, Denlinger JD, Kim SG, Kim SW, Seo J, Kim Y. Topological Fermi-arc surface state covered by floating electrons on a two-dimensional electride. Nat Commun 2024; 15:5615. [PMID: 38965217 PMCID: PMC11224405 DOI: 10.1038/s41467-024-49841-6] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/23/2024] [Accepted: 06/19/2024] [Indexed: 07/06/2024] Open
Abstract
Two-dimensional electrides can acquire topologically non-trivial phases due to intriguing interplay between the cationic atomic layers and anionic electron layers. However, experimental evidence of topological surface states has yet to be verified. Here, via angle-resolved photoemission spectroscopy (ARPES) and scanning tunnelling microscopy (STM), we probe the magnetic Weyl states of the ferromagnetic electride [Gd2C]2+·2e-. In particular, the presence of Weyl cones and Fermi-arc states is demonstrated through photon energy-dependent ARPES measurements, agreeing with theoretical band structure calculations. Notably, the STM measurements reveal that the Fermi-arc states exist underneath a floating quantum electron liquid on the top Gd layer, forming double-stacked surface states in a heterostructure. Our work thus not only unveils the non-trivial topology of the [Gd2C]2+·2e- electride but also realizes a surface heterostructure that can host phenomena distinct from the bulk.
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Affiliation(s)
- Chan-Young Lim
- Department of Physics, Korea Advanced Institute of Science and Technology, Daejeon, 34141, South Korea
- Donostia International Physics Center (DIPC), 20018, San Sebastián/Donostia, Spain
| | - Min-Seok Kim
- Department of Physics and Chemistry, Daegu Gyeongbuk Institute of Science and Technology, Daegu, 42988, South Korea
| | - Dong Cheol Lim
- Department of Energy Science, Sungkyunkwan University, Suwon, 16419, South Korea
- Center for Electride Materials, Sungkyunkwan University, Suwon, 16419, South Korea
| | - Sunghun Kim
- Department of Physics, Ajou University, Suwon, 16499, South Korea
| | - Yeonghoon Lee
- Quantum Spin Team, Korea Research Institute of Standards and Science, Daejeon, 34113, South Korea
| | - Jaehoon Cha
- Department of Physics, Korea Advanced Institute of Science and Technology, Daejeon, 34141, South Korea
| | - Gyubin Lee
- Department of Physics, Korea Advanced Institute of Science and Technology, Daejeon, 34141, South Korea
| | - Sang Yong Song
- Department of Physics and Chemistry, Daegu Gyeongbuk Institute of Science and Technology, Daegu, 42988, South Korea
| | - Dinesh Thapa
- Department of Chemistry and Biochemistry, North Dakota State University, Fargo, ND, 58108, USA
| | - Jonathan D Denlinger
- Advanced Light Source, Lawrence Berkeley National Laboratory, Berkeley, CA, 94720, USA
| | - Seong-Gon Kim
- Department of Physics & Astronomy and Center for Computational Sciences, Mississippi State University, Mississippi State, MS, 39792, USA.
| | - Sung Wng Kim
- Department of Energy Science, Sungkyunkwan University, Suwon, 16419, South Korea.
- Center for Electride Materials, Sungkyunkwan University, Suwon, 16419, South Korea.
| | - Jungpil Seo
- Department of Physics and Chemistry, Daegu Gyeongbuk Institute of Science and Technology, Daegu, 42988, South Korea.
| | - Yeongkwan Kim
- Department of Physics, Korea Advanced Institute of Science and Technology, Daejeon, 34141, South Korea.
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10
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Zhang J, Shen S, Puggioni D, Wang M, Sha H, Xu X, Lyu Y, Peng H, Xing W, Walters LN, Liu L, Wang Y, Hou D, Xi C, Pi L, Ishizuka H, Kotani Y, Kimata M, Nojiri H, Nakamura T, Liang T, Yi D, Nan T, Zang J, Sheng Z, He Q, Zhou S, Nagaosa N, Nan CW, Tokura Y, Yu R, Rondinelli JM, Yu P. A correlated ferromagnetic polar metal by design. NATURE MATERIALS 2024; 23:912-919. [PMID: 38605196 DOI: 10.1038/s41563-024-01856-6] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 06/28/2023] [Accepted: 03/11/2024] [Indexed: 04/13/2024]
Abstract
Polar metals have recently garnered increasing interest because of their promising functionalities. Here we report the experimental realization of an intrinsic coexisting ferromagnetism, polar distortion and metallicity in quasi-two-dimensional Ca3Co3O8. This material crystallizes with alternating stacking of oxygen tetrahedral CoO4 monolayers and octahedral CoO6 bilayers. The ferromagnetic metallic state is confined within the quasi-two-dimensional CoO6 layers, and the broken inversion symmetry arises simultaneously from the Co displacements. The breaking of both spatial-inversion and time-reversal symmetries, along with their strong coupling, gives rise to an intrinsic magnetochiral anisotropy with exotic magnetic field-free non-reciprocal electrical resistivity. An extraordinarily robust topological Hall effect persists over a broad temperature-magnetic field phase space, arising from dipole-induced Rashba spin-orbit coupling. Our work not only provides a rich platform to explore the coupling between polarity and magnetism in a metallic system, with extensive potential applications, but also defines a novel design strategy to access exotic correlated electronic states.
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Affiliation(s)
- Jianbing Zhang
- State Key Laboratory of Low Dimensional Quantum Physics and Department of Physics, Tsinghua University, Beijing, China
| | - Shengchun Shen
- State Key Laboratory of Low Dimensional Quantum Physics and Department of Physics, Tsinghua University, Beijing, China
| | - Danilo Puggioni
- Department of Materials Science and Engineering, Northwestern University, Evanston, IL, USA
| | - Meng Wang
- State Key Laboratory of Low Dimensional Quantum Physics and Department of Physics, Tsinghua University, Beijing, China
| | - Haozhi Sha
- State Key Laboratory of New Ceramics and Fine Processing, School of Materials Science and Engineering, Tsinghua University, Beijing, China
- MOE Key Laboratory of Advanced Materials, Tsinghua University, Beijing, China
| | - Xueli Xu
- High Magnetic Field Laboratory, HFIPS, Anhui, Chinese Academy of Sciences, Hefei, China
| | - Yingjie Lyu
- State Key Laboratory of Low Dimensional Quantum Physics and Department of Physics, Tsinghua University, Beijing, China
| | - Huining Peng
- State Key Laboratory of Low Dimensional Quantum Physics and Department of Physics, Tsinghua University, Beijing, China
| | - Wandong Xing
- State Key Laboratory of New Ceramics and Fine Processing, School of Materials Science and Engineering, Tsinghua University, Beijing, China
- MOE Key Laboratory of Advanced Materials, Tsinghua University, Beijing, China
| | - Lauren N Walters
- Department of Materials Science and Engineering, Northwestern University, Evanston, IL, USA
| | - Linhan Liu
- State Key Laboratory of New Ceramics and Fine Processing, School of Materials Science and Engineering, Tsinghua University, Beijing, China
- MOE Key Laboratory of Advanced Materials, Tsinghua University, Beijing, China
| | - Yujia Wang
- State Key Laboratory of Low Dimensional Quantum Physics and Department of Physics, Tsinghua University, Beijing, China
| | - De Hou
- High Magnetic Field Laboratory, HFIPS, Anhui, Chinese Academy of Sciences, Hefei, China
| | - Chuanying Xi
- High Magnetic Field Laboratory, HFIPS, Anhui, Chinese Academy of Sciences, Hefei, China
| | - Li Pi
- High Magnetic Field Laboratory, HFIPS, Anhui, Chinese Academy of Sciences, Hefei, China
| | - Hiroaki Ishizuka
- Department of Physics, Tokyo Institute of Technology, Tokyo, Japan
| | - Yoshinori Kotani
- Center for Synchrotron Radiation Research, Japan Synchrotron Radiation Research Institute, Hyogo, Japan
| | - Motoi Kimata
- Institute of Materials Research, Tohoku University, Sendai, Japan
| | - Hiroyuki Nojiri
- Institute of Materials Research, Tohoku University, Sendai, Japan
| | - Tetsuya Nakamura
- International Center for Synchrotron Radiation Innovation Smart, Tohoku University, Sendai, Japan
| | - Tian Liang
- State Key Laboratory of Low Dimensional Quantum Physics and Department of Physics, Tsinghua University, Beijing, China
- RIKEN Center for Emergent Matter Science (CEMS), Wako, Japan
- Frontier Science Center for Quantum Information, Beijing, China
| | - Di Yi
- State Key Laboratory of New Ceramics and Fine Processing, School of Materials Science and Engineering, Tsinghua University, Beijing, China
| | - Tianxiang Nan
- School of Integrated Circuits, Beijing National Research Center for Information Science and Technology, Tsinghua University, Beijing, China
| | - Jiadong Zang
- Department of Physics and Astronomy, University of New Hampshire, Durham, NH, USA
| | - Zhigao Sheng
- High Magnetic Field Laboratory, HFIPS, Anhui, Chinese Academy of Sciences, Hefei, China
| | - Qing He
- Department of Physics, Durham University, Durham, UK
| | - Shuyun Zhou
- State Key Laboratory of Low Dimensional Quantum Physics and Department of Physics, Tsinghua University, Beijing, China
- Frontier Science Center for Quantum Information, Beijing, China
| | - Naoto Nagaosa
- RIKEN Center for Emergent Matter Science (CEMS), Wako, Japan
- Department of Applied Physics, University of Tokyo, Tokyo, Japan
| | - Ce-Wen Nan
- State Key Laboratory of New Ceramics and Fine Processing, School of Materials Science and Engineering, Tsinghua University, Beijing, China
| | - Yoshinori Tokura
- RIKEN Center for Emergent Matter Science (CEMS), Wako, Japan
- Department of Applied Physics, University of Tokyo, Tokyo, Japan
| | - Rong Yu
- State Key Laboratory of New Ceramics and Fine Processing, School of Materials Science and Engineering, Tsinghua University, Beijing, China.
- MOE Key Laboratory of Advanced Materials, Tsinghua University, Beijing, China.
| | - James M Rondinelli
- Department of Materials Science and Engineering, Northwestern University, Evanston, IL, USA.
| | - Pu Yu
- State Key Laboratory of Low Dimensional Quantum Physics and Department of Physics, Tsinghua University, Beijing, China.
- RIKEN Center for Emergent Matter Science (CEMS), Wako, Japan.
- Frontier Science Center for Quantum Information, Beijing, China.
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11
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Fonseca AG, Vaidya S, Christensen T, Rechtsman MC, Hughes TL, Soljačić M. Weyl Points on Nonorientable Manifolds. PHYSICAL REVIEW LETTERS 2024; 132:266601. [PMID: 38996300 DOI: 10.1103/physrevlett.132.266601] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 12/16/2023] [Revised: 04/01/2024] [Accepted: 05/03/2024] [Indexed: 07/14/2024]
Abstract
Weyl fermions are hypothetical chiral particles that can also manifest as excitations near three-dimensional band crossing points in lattice systems. These quasiparticles are subject to the Nielsen-Ninomiya "no-go" theorem when placed on a lattice, requiring the total chirality across the Brillouin zone to vanish. This constraint results from the topology of the (orientable) manifold on which they exist. Here, we ask to what extent the concepts of topology and chirality of Weyl points remain well defined when the underlying manifold is nonorientable. We show that the usual notion of chirality becomes ambiguous in this setting, allowing for systems with a nonzero total chirality. This circumvention of the Nielsen-Ninomiya theorem stems from a generic discontinuity of the vector field whose zeros are Weyl points. Furthermore, we discover that Weyl points on nonorientable manifolds carry an additional Z_{2} topological invariant which satisfies a different no-go theorem. We implement such Weyl points by imposing a nonsymmorphic symmetry in the momentum space of lattice models. Finally, we experimentally realize all aspects of their phenomenology in a photonic platform with synthetic momenta. Our work highlights the subtle but crucial interplay between the topology of quasiparticles and of their underlying manifold.
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Affiliation(s)
- André Grossi Fonseca
- Department of Physics, Massachusetts Institute of Technology, Cambridge, Massachusetts 02139, USA
| | - Sachin Vaidya
- Department of Physics, Massachusetts Institute of Technology, Cambridge, Massachusetts 02139, USA
| | - Thomas Christensen
- Department of Electrical and Photonics Engineering, Technical University of Denmark, Kongens Lyngby 2800, Denmark
| | - Mikael C Rechtsman
- Department of Physics, The Pennsylvania State University, University Park, Pennsylvania 16802, USA
| | - Taylor L Hughes
- Department of Physics and Institute for Condensed Matter Theory, University of Illinois at Urbana-Champaign, Urbana, Illinois 61801, USA
| | - Marin Soljačić
- Department of Physics, Massachusetts Institute of Technology, Cambridge, Massachusetts 02139, USA
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12
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Liu Z, Zhang P, Mei C, Liang XT, Jha A, Duan HG. Transient Chiral Dynamics in the Fenna-Matthews-Olson Complex Revealed by Two-Dimensional Circular Dichroism Spectroscopy. J Phys Chem Lett 2024; 15:6550-6559. [PMID: 38885182 DOI: 10.1021/acs.jpclett.4c01179] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 06/20/2024]
Abstract
Chirality plays a pivotal role across scientific disciplines with profound implications spanning light-matter interactions, molecular recognition, and natural evolutionary processes. This study delves into the active influence of molecular chirality on exciton energy transfer within photosynthetic protein complexes, focusing on the Fenna-Matthews-Olson (FMO) complex. Employing two-dimensional circular dichroism (2DCD) spectroscopy, we investigate the transient chiral dynamics of excitons during energy transfer processes within the FMO complex. Our approach, incorporating pulse information into population dynamics based on the third-order response function, facilitates the calculation of 2DCD spectra and dynamics. This enables the extraction of chiral contributions to excitonic energy transfer and the examination of electronic wave functions. We demonstrate that 2DCD spectra offer excitation energies that are better resolved than those from conventional two-dimensional electronic spectroscopy. These findings deepen our understanding of exciton energy transfer mechanisms in natural photosynthesis, emphasizing the potential of 2DCD spectroscopy as a powerful tool for unraveling the chiral contribution to exciton dynamics.
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Affiliation(s)
- Zihui Liu
- Department of Physics, School of Physical Science and Technology, Ningbo University, Ningbo 315211, P. R. China
| | - Panpan Zhang
- Department of Physics, School of Physical Science and Technology, Ningbo University, Ningbo 315211, P. R. China
| | - Chao Mei
- Department of Physics, School of Physical Science and Technology, Ningbo University, Ningbo 315211, P. R. China
| | - Xian-Ting Liang
- Department of Physics, School of Physical Science and Technology, Ningbo University, Ningbo 315211, P. R. China
| | - Ajay Jha
- Rosalind Franklin Institute, Harwell Campus, OX11 0QX Didcot, U.K
- Department of Pharmacology, University of Oxford, OX1 3QT Oxford, U.K
| | - Hong-Guang Duan
- Department of Physics, School of Physical Science and Technology, Ningbo University, Ningbo 315211, P. R. China
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13
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Shin BG, Park JH, Kong J, Jung SJ, Song YJ. Charged Black-Hole-Like Electronic Structure Driven by Geometric Potential of 2D Semiconductors. ADVANCED MATERIALS (DEERFIELD BEACH, FLA.) 2024:e2402373. [PMID: 38935940 DOI: 10.1002/adma.202402373] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 02/15/2024] [Revised: 06/20/2024] [Indexed: 06/29/2024]
Abstract
One of the exotic expectations in the 2D curved spacetime is the geometric potential from the curvature of the 2D space, still possessing unsolved fundamental questions through Dirac quantization. The atomically thin 2D materials are promising for the realization of the geometric potential, but the geometric potential in 2D materials is not identified experimentally. Here, the curvature-induced ring-patterned bound states are observed in structurally deformed 2D semiconductors and formulated the modified geometric potential for the curvature effect, which demonstrates the ring-shape bound states with angular momentum. The formulated modified geometric potential is analogous to the effective potential of a rotating charged black hole. Density functional theory and tight-binding calculations are performed, which quantitatively agree well with the results of the modified geometric potential. The modified geometric potential is described by modified Gaussian and mean curvatures, corresponding to the curvature-induced changes in spin-orbit interaction and band gap, respectively. Even for complex structural deformation, the geometric potential solves the complexity, which aligns well with experimental results. The understanding of the modified geometric potential provides us with an intuitive clue for quantum transport and a key factor for new quantum applications such as valleytronics, spintronics, and straintronics in 2D semiconductors.
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Affiliation(s)
- Bong Gyu Shin
- Department of Nano Science and Technology, Sungkyunkwan University (SKKU), Suwon, 16419, Republic of Korea
- SKKU Advanced Institute of Nanotechnology (SAINT), Sungkyunkwan University (SKKU), Suwon, 16419, Republic of Korea
| | - Ji-Hoon Park
- Department of Electrical Engineering and Computer Science, Massachusetts Institute of Technology, Cambridge, Massachusetts, 02139, USA
| | - Jing Kong
- Department of Electrical Engineering and Computer Science, Massachusetts Institute of Technology, Cambridge, Massachusetts, 02139, USA
| | - Soon Jung Jung
- Max Planck Institute for Solid State Research, Heisenbergstrasse 1, 70569, Stuttgart, Germany
| | - Young Jae Song
- Department of Nano Science and Technology, Sungkyunkwan University (SKKU), Suwon, 16419, Republic of Korea
- SKKU Advanced Institute of Nanotechnology (SAINT), Sungkyunkwan University (SKKU), Suwon, 16419, Republic of Korea
- Department of Nano Engineering, Sungkyunkwan University (SKKU), Suwon, 16419, Republic of Korea
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14
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Zhang Y, Ma Y, Sun W, Li W, Li G. Structural and Electronic Chirality in Inorganic Crystals: from Construction to Application. Chemistry 2024; 30:e202400436. [PMID: 38571318 DOI: 10.1002/chem.202400436] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/31/2024] [Revised: 03/31/2024] [Accepted: 04/03/2024] [Indexed: 04/05/2024]
Abstract
Chirality represents a fundamental characteristic inherent in nature, playing a pivotal role in the emergence of homochirality and the origin of life. While the principles of chirality in organic chemistry are well-documented, the exploration of chirality within inorganic crystal structures continues to evolve. This ongoing development is primarily due to the diverse nature of crystal/amorphous structures in inorganic materials, along with the intricate symmetrical and asymmetrical relationships in the geometry of their constituent atoms. In this review, we commence with a summary of the foundational concept of chirality in molecules and solid states matters. This is followed by an introduction of structural chirality and electronic chirality in three-dimensional and two-dimensional inorganic materials. The construction of chirality in inorganic materials is classified into physical photolithography, wet-chemistry method, self-assembly, and chiral imprinting. Highlighting the significance of this field, we also summarize the research progress of chiral inorganic materials for applications in optical activity, enantiomeric recognition and chiral sensing, selective adsorption and enantioselective separation, asymmetric synthesis and catalysis, and chirality-induced spin polarization. This review aims to provide a reference for ongoing research in chiral inorganic materials and potentially stimulate innovative strategies and novel applications in the realm of chirality.
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Affiliation(s)
- Yudi Zhang
- CAS Key Laboratory of Magnetic Materials and Devices, and Zhejiang Province Key Laboratory of Magnetic Materials and Application Technology, Ningbo Institute of Materials Technology and Engineering, Chinese Academy of Sciences, Ningbo, 315201, China
- University of Chinese Academy of Sciences, 19 A Yuquan Rd, Shijingshan District, Beijing, 100049, China
| | - Yuzhe Ma
- CAS Key Laboratory of Magnetic Materials and Devices, and Zhejiang Province Key Laboratory of Magnetic Materials and Application Technology, Ningbo Institute of Materials Technology and Engineering, Chinese Academy of Sciences, Ningbo, 315201, China
- University of Chinese Academy of Sciences, 19 A Yuquan Rd, Shijingshan District, Beijing, 100049, China
| | - Wen Sun
- CAS Key Laboratory of Magnetic Materials and Devices, and Zhejiang Province Key Laboratory of Magnetic Materials and Application Technology, Ningbo Institute of Materials Technology and Engineering, Chinese Academy of Sciences, Ningbo, 315201, China
- University of Chinese Academy of Sciences, 19 A Yuquan Rd, Shijingshan District, Beijing, 100049, China
| | - Wei Li
- CISRI & NIMTE Joint Innovation Center for Rare Earth Permanent Magnets, Chinese Academy of Sciences, Ningbo Institute of Material Technology and Engineering, Ningbo, 315201, China
| | - Guowei Li
- CAS Key Laboratory of Magnetic Materials and Devices, and Zhejiang Province Key Laboratory of Magnetic Materials and Application Technology, Ningbo Institute of Materials Technology and Engineering, Chinese Academy of Sciences, Ningbo, 315201, China
- University of Chinese Academy of Sciences, 19 A Yuquan Rd, Shijingshan District, Beijing, 100049, China
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15
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Rehaag TJ, Bell GR. Heteroepitaxial Growth of InBi(001). Molecules 2024; 29:2825. [PMID: 38930890 PMCID: PMC11206747 DOI: 10.3390/molecules29122825] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/03/2024] [Revised: 05/28/2024] [Accepted: 06/05/2024] [Indexed: 06/28/2024] Open
Abstract
InBi is a topological nodal line semimetal with strong spin-orbit coupling. It is epitaxially compatible with III-V semiconductors and, hence, an attractive material for topological spintronics. However, growth by molecular beam epitaxy (MBE) is challenging owing to the low melting point of InBi and the tendency to form droplets. We investigate approaches for epitaxial growth of InBi films on InSb(001) substrates using MBE and periodic supply epitaxy (PSE). It was not possible to achieve planar, stoichiometric InBi heteroepitaxy using MBE growth over the parameter space explored. However, pseudomorphic growth of ultra-thin InBi(001) layers could be achieved by PSE on InSb(001). A remarkable change to the in-plane epitaxial orientation is observed.
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Affiliation(s)
| | - Gavin R. Bell
- Department of Physics, University of Warwick, Coventry CV4 7AL, UK;
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16
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Kumar R, Singh M. Topological phase transition and tunable surface states in YBi. JOURNAL OF PHYSICS. CONDENSED MATTER : AN INSTITUTE OF PHYSICS JOURNAL 2024; 36:345601. [PMID: 38740046 DOI: 10.1088/1361-648x/ad4aae] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 02/29/2024] [Accepted: 05/13/2024] [Indexed: 05/16/2024]
Abstract
A unique co-existence of extremely large magnetoresistance (XMR) and topological characteristics in non-magnetic rare-earth monopnictides has stimulated intensive research on these materials. Yttrium monobismuthide (YBi) has been reported to exhibit XMR up to 105% but its topological properties still need clarification. Here we use the hybrid density functional theory to probe the structural, electronic, and topological properties of YBi in detail. We observe that YBi is topologically trivial semimetal at ambient pressure which is in accordance with reported experimental results. The topological phase transitions i.e. trivial to non-trivial are obtained with volumetric pressure of 6.5 GPa and 3% of epitaxial strain. These topological phase transitions are well within the structural phase transition of YBi (24.5 GPa). The topological non-trivial state is characterized by band inversions amongY-dband andBi-pband atΓ-andX-pointwhich is further verified with the help of surface band structure along (001) plane. The Z2topological invariants are calculated with the help of product of parities and evolution of Wannier charge centers. The occurrence of non-trivial phase in YBi with a relatively small epitaxial strain, which a thin film geometry can naturally have, make it an ideal candidate to probe inter-relationship between XMR and non-trivial topology.
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Affiliation(s)
- Ramesh Kumar
- Department of Applied Physics, Delhi Technological University, New Delhi 110042, India
| | - Mukhtiyar Singh
- Department of Applied Physics, Delhi Technological University, New Delhi 110042, India
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17
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Tsigaridas GN, Kechriniotis AI, Tsonos CA, Delibasis KK. A Proposed Device for Controlling the Flow of Information Based on Weyl Fermions. SENSORS (BASEL, SWITZERLAND) 2024; 24:3361. [PMID: 38894152 PMCID: PMC11175101 DOI: 10.3390/s24113361] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 04/30/2024] [Revised: 05/18/2024] [Accepted: 05/21/2024] [Indexed: 06/21/2024]
Abstract
In this work we propose a novel device for controlling the flow of information using Weyl fermions. Based on a previous work by our group, we show that it is possible to fully control the flow of Weyl fermions on several different channels by applying an electric field perpendicular to the direction of motion of the particles on each channel. In this way, we can transmit information as logical bits, depending on the existence or not of a Weyl current on each channel. We also show that the response time of this device is exceptionally low, less than 1 ps, for typical values of its parameters, allowing for the control of the flow of information at extremely high rates of the order of 100 Petabits per second. Alternatively, this device could also operate as an electric field sensor. In addition, we demonstrate that Weyl fermions can be efficiently guided through the proposed device using appropriate magnetic fields. Finally, we discuss some particularly interesting remarks regarding the electromagnetic interactions of high-energy particles.
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Affiliation(s)
- Georgios N. Tsigaridas
- Department of Physics, School of Applied Mathematical and Physical Sciences, National Technical University of Athens, GR-15772 Athens, Greece
| | | | - Christos A. Tsonos
- Department of Physics, University of Thessaly, GR-35100 Lamia, Greece; (A.I.K.); (C.A.T.)
| | - Konstantinos K. Delibasis
- Department of Computer Science and Biomedical Informatics, University of Thessaly, GR-35131 Lamia, Greece;
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18
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Bonilla DA, Muñoz E. Thermoelectric transport in Weyl semimetals under a uniform concentration of torsional dislocations. NANOSCALE ADVANCES 2024; 6:2701-2712. [PMID: 38752144 PMCID: PMC11093277 DOI: 10.1039/d4na00056k] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 01/19/2024] [Accepted: 04/01/2024] [Indexed: 05/18/2024]
Abstract
In this article, we present an effective continuum model for a Weyl semimetal, to calculate its thermal and thermoelectric transport coefficients in the presence of a uniform concentration of torsional dislocations. We model each dislocation as a cylindrical region of finite radius a, where the corresponding elastic strain is described as a gauge field leading to a local pseudo-magnetic field. The transport coefficients are obtained by a combination of scattering theory, Green's functions and the Kubo formulae in the linear response regime. We applied our theoretical results to predict the electrical and thermal conductivities as well as the Seebeck coefficient for several transition metal monopnictides, i.e. TaAs, TaP, NbAs and NbP.
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Affiliation(s)
- Daniel A Bonilla
- Facultad de Física, Pontificia Universidad Católica de Chile Vicuña Mackenna 4860 Santiago Chile
| | - Enrique Muñoz
- Facultad de Física, Pontificia Universidad Católica de Chile Vicuña Mackenna 4860 Santiago Chile
- Center for Nanotechnology and Advanced Materials CIEN-UC Avenida Vicuña Mackenna 4860 Santiago Chile
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19
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Wang T, Sun H, Li X, Zhang L. Chiral Phonons: Prediction, Verification, and Application. NANO LETTERS 2024; 24:4311-4318. [PMID: 38587210 DOI: 10.1021/acs.nanolett.4c00606] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 04/09/2024]
Abstract
Chirality as an asymmetric property is prevalent in nature. In physics, the chirality of the elementary particles that make up matter has been widely studied and discussed, and nowadays, the concept has developed into the field of phonons. As an important fundamental excitation in condensed matter physics, phonons are traditionally considered to be linearly polarized and nonchiral. However, in recent years, the chirality of phonons has been revealed and further experimentally verified. The discovery has triggered a series of new explorations and developments in phonon-related physical processes. This Mini-Review provides an overview of the theoretical prediction of chiral phonons and multiple experimental detection methods and highlights the current key issues in the application of chiral phonons in different fields.
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Affiliation(s)
- Tingting Wang
- Phonon Engineering Research Center of Jiangsu Province, Ministry of Education Key Laboratory of NSLSCS, Center for Quantum Transport and Thermal Energy Science, Institute of Physics Frontiers and Interdisciplinary Sciences, School of Physics and Technology, Nanjing Normal University, Nanjing 210023, China
| | - Hong Sun
- Phonon Engineering Research Center of Jiangsu Province, Ministry of Education Key Laboratory of NSLSCS, Center for Quantum Transport and Thermal Energy Science, Institute of Physics Frontiers and Interdisciplinary Sciences, School of Physics and Technology, Nanjing Normal University, Nanjing 210023, China
| | - Xiaozhe Li
- Phonon Engineering Research Center of Jiangsu Province, Ministry of Education Key Laboratory of NSLSCS, Center for Quantum Transport and Thermal Energy Science, Institute of Physics Frontiers and Interdisciplinary Sciences, School of Physics and Technology, Nanjing Normal University, Nanjing 210023, China
| | - Lifa Zhang
- Phonon Engineering Research Center of Jiangsu Province, Ministry of Education Key Laboratory of NSLSCS, Center for Quantum Transport and Thermal Energy Science, Institute of Physics Frontiers and Interdisciplinary Sciences, School of Physics and Technology, Nanjing Normal University, Nanjing 210023, China
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20
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Bouhiron JB, Fabre A, Liu Q, Redon Q, Mittal N, Satoor T, Lopes R, Nascimbene S. Realization of an atomic quantum Hall system in four dimensions. Science 2024; 384:223-227. [PMID: 38603489 DOI: 10.1126/science.adf8459] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/16/2022] [Accepted: 02/14/2024] [Indexed: 04/13/2024]
Abstract
Modern condensed matter physics relies on the concept of topology to classify matter, from quantum Hall systems to topological insulators. Engineered systems, benefiting from synthetic dimensions, can potentially give access to topological states predicted in dimensions D > 3. We report the realization of an atomic quantum Hall system evolving in four dimensions (4D), with two spatial dimensions and two synthetic ones encoded in the large spin of dysprosium atoms. We measure the nontrivial topological index of the ground band through a full characterization of the nonlinear electromagnetic response and observe the associated anisotropic hyperedge modes. We also excite nonplanar cyclotron motion, in contrast to the planar orbits in D ≤ 3. Our work may enable the investigation of strongly correlated topological liquids in 4D, generalizing fractional quantum Hall states.
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Affiliation(s)
- Jean-Baptiste Bouhiron
- Laboratoire Kastler Brossel, Collège de France, CNRS, ENS-PSL University, Sorbonne Université, 11 Place Marcelin Berthelot, 75005 Paris, France
| | - Aurélien Fabre
- Laboratoire Kastler Brossel, Collège de France, CNRS, ENS-PSL University, Sorbonne Université, 11 Place Marcelin Berthelot, 75005 Paris, France
| | - Qi Liu
- Laboratoire Kastler Brossel, Collège de France, CNRS, ENS-PSL University, Sorbonne Université, 11 Place Marcelin Berthelot, 75005 Paris, France
| | - Quentin Redon
- Laboratoire Kastler Brossel, Collège de France, CNRS, ENS-PSL University, Sorbonne Université, 11 Place Marcelin Berthelot, 75005 Paris, France
| | - Nehal Mittal
- Laboratoire Kastler Brossel, Collège de France, CNRS, ENS-PSL University, Sorbonne Université, 11 Place Marcelin Berthelot, 75005 Paris, France
| | - Tanish Satoor
- Laboratoire Kastler Brossel, Collège de France, CNRS, ENS-PSL University, Sorbonne Université, 11 Place Marcelin Berthelot, 75005 Paris, France
| | - Raphael Lopes
- Laboratoire Kastler Brossel, Collège de France, CNRS, ENS-PSL University, Sorbonne Université, 11 Place Marcelin Berthelot, 75005 Paris, France
| | - Sylvain Nascimbene
- Laboratoire Kastler Brossel, Collège de France, CNRS, ENS-PSL University, Sorbonne Université, 11 Place Marcelin Berthelot, 75005 Paris, France
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21
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Ghosh R, Mandal I. Direction-dependent conductivity in planar Hall set-ups with tilted Weyl/multi-Weyl semimetals. JOURNAL OF PHYSICS. CONDENSED MATTER : AN INSTITUTE OF PHYSICS JOURNAL 2024; 36:275501. [PMID: 38547533 DOI: 10.1088/1361-648x/ad38fa] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 02/19/2024] [Accepted: 03/28/2024] [Indexed: 04/09/2024]
Abstract
We compute the magnetoelectric conductivity tensors in planar Hall set-ups, which are built with tilted Weyl semimetals (WSMs) and multi-Weyl semimetals (mWSMs), considering all possible relative orientations of the electromagnetic fields (EandB) and the direction of the tilt. The non-Drude part of the response arises from a nonzero Berry curvature in the vicinity of the WSM/mWSM node under consideration. Only in the presence of a nonzero tilt do we find linear-in-|B|terms in set-ups where the tilt-axis is not perpendicular to the plane spanned byEandB. The advantage of the emergence of the linear-in-|B|terms is that, unlike the various|B|2-dependent terms that can contribute to experimental observations, they have purely a topological origin, and they dominate the overall response-characteristics in the realistic parameter regimes. The important signatures of these terms are that they (1) change the periodicity of the response fromπto 2π, when we consider their dependence on the angleθbetweenEandB; and (2) lead to an overall change in sign of the conductivity depending onθ, when measured with respect to theB=0case.
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Affiliation(s)
- Rahul Ghosh
- Department of Physics, Shiv Nadar Institution of Eminence (SNIoE), Gautam Buddha Nagar, Uttar Pradesh 201314, India
| | - Ipsita Mandal
- Department of Physics, Shiv Nadar Institution of Eminence (SNIoE), Gautam Buddha Nagar, Uttar Pradesh 201314, India
- Freiburg Institute for Advanced Studies (FRIAS), University of Freiburg, D-79104 Freiburg, Germany
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22
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Tzschaschel C, Qiu JX, Gao XJ, Li HC, Guo C, Yang HY, Zhang CP, Xie YM, Liu YF, Gao A, Bérubé D, Dinh T, Ho SC, Fang Y, Huang F, Nordlander J, Ma Q, Tafti F, Moll PJW, Law KT, Xu SY. Nonlinear optical diode effect in a magnetic Weyl semimetal. Nat Commun 2024; 15:3017. [PMID: 38589414 PMCID: PMC11271640 DOI: 10.1038/s41467-024-47291-8] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/19/2023] [Accepted: 03/27/2024] [Indexed: 04/10/2024] Open
Abstract
Diode effects are of great interest for both fundamental physics and modern technologies. Electrical diode effects (nonreciprocal transport) have been observed in Weyl systems. Optical diode effects arising from the Weyl fermions have been theoretically considered but not probed experimentally. Here, we report the observation of a nonlinear optical diode effect (NODE) in the magnetic Weyl semimetal CeAlSi, where the magnetization introduces a pronounced directionality in the nonlinear optical second-harmonic generation (SHG). We demonstrate a six-fold change of the measured SHG intensity between opposite propagation directions over a bandwidth exceeding 250 meV. Supported by density-functional theory, we establish the linearly dispersive bands emerging from Weyl nodes as the origin of this broadband effect. We further demonstrate current-induced magnetization switching and thus electrical control of the NODE. Our results advance ongoing research to identify novel nonlinear optical/transport phenomena in magnetic topological materials and further opens new pathways for the unidirectional manipulation of light.
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Affiliation(s)
- Christian Tzschaschel
- Department of Chemistry and Chemical Biology, Harvard University, Cambridge, MA, 02138, USA.
- Max-Born Institute for Nonlinear Optics and Short Pulse Spectroscopy, Berlin, Germany.
| | - Jian-Xiang Qiu
- Department of Chemistry and Chemical Biology, Harvard University, Cambridge, MA, 02138, USA
| | - Xue-Jian Gao
- Department of Physics, Hong Kong University of Science and Technology, Clear Water Bay, Hong Kong, China
| | - Hou-Chen Li
- Department of Chemistry and Chemical Biology, Harvard University, Cambridge, MA, 02138, USA
| | - Chunyu Guo
- Max Planck Institute for the Structure and Dynamics of Matter, Hamburg, Germany
- Laboratory of Quantum Materials (QMAT), Institute of Materials (IMX), École Polytechnique Fédérale de Lausanne (EPFL), CH-1015, Lausanne, Switzerland
| | - Hung-Yu Yang
- Department of Physics, Boston College, Chestnut Hill, MA, USA
| | - Cheng-Ping Zhang
- Department of Physics, Hong Kong University of Science and Technology, Clear Water Bay, Hong Kong, China
| | - Ying-Ming Xie
- Department of Physics, Hong Kong University of Science and Technology, Clear Water Bay, Hong Kong, China
| | - Yu-Fei Liu
- Department of Chemistry and Chemical Biology, Harvard University, Cambridge, MA, 02138, USA
| | - Anyuan Gao
- Department of Chemistry and Chemical Biology, Harvard University, Cambridge, MA, 02138, USA
| | - Damien Bérubé
- Department of Chemistry and Chemical Biology, Harvard University, Cambridge, MA, 02138, USA
| | - Thao Dinh
- Department of Chemistry and Chemical Biology, Harvard University, Cambridge, MA, 02138, USA
| | - Sheng-Chin Ho
- Department of Chemistry and Chemical Biology, Harvard University, Cambridge, MA, 02138, USA
| | - Yuqiang Fang
- State Key Laboratory of High Performance Ceramics and Superfine Microstructure, Shanghai Institute of Ceramics, Chinese Academy of Science, Shanghai, China
- State Key Laboratory of Rare Earth Materials Chemistry and Applications, College of Chemistry and Molecular Engineering Peking University, Beijing, China
| | - Fuqiang Huang
- State Key Laboratory of High Performance Ceramics and Superfine Microstructure, Shanghai Institute of Ceramics, Chinese Academy of Science, Shanghai, China
- State Key Laboratory of Rare Earth Materials Chemistry and Applications, College of Chemistry and Molecular Engineering Peking University, Beijing, China
| | | | - Qiong Ma
- Department of Physics, Boston College, Chestnut Hill, MA, USA
- CIFAR Azrieli Global Scholars program, CIFAR, Toronto, Ontario, Canada
| | - Fazel Tafti
- Department of Physics, Boston College, Chestnut Hill, MA, USA
| | - Philip J W Moll
- Max Planck Institute for the Structure and Dynamics of Matter, Hamburg, Germany
- Laboratory of Quantum Materials (QMAT), Institute of Materials (IMX), École Polytechnique Fédérale de Lausanne (EPFL), CH-1015, Lausanne, Switzerland
| | - Kam Tuen Law
- Department of Physics, Hong Kong University of Science and Technology, Clear Water Bay, Hong Kong, China
| | - Su-Yang Xu
- Department of Chemistry and Chemical Biology, Harvard University, Cambridge, MA, 02138, USA.
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23
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Song W, Lin Z, Ji J, Sun J, Chen C, Wu S, Huang C, Yuan L, Zhu S, Li T. Bound-Extended Mode Transition in Type-II Synthetic Photonic Weyl Heterostructures. PHYSICAL REVIEW LETTERS 2024; 132:143801. [PMID: 38640373 DOI: 10.1103/physrevlett.132.143801] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 10/25/2023] [Accepted: 03/06/2024] [Indexed: 04/21/2024]
Abstract
Photonic structures with Weyl points (WPs), including type I and type II, promise nontrivial surface modes and intriguing light manipulations for their three-dimensional topological bands. While previous studies mainly focus on exploring WPs in a uniform Weyl structure, here we establish Weyl heterostructures (i.e., a nonuniform Weyl lattice) with different rotational orientations in the synthetic dimension by nanostructured photonic waveguides. In this work, we unveil a transition between bound and extended modes on the interface of type-II Weyl heterostructures by tuning their rotational phases, despite the reversed topological order across the interface. This mode transition is also manifested from the total transmission to total reflection at the interface. All of these unconventional effects are attributed to the tilted dispersion of type-II Weyl band structure that can lead to mismatched bands and gaps across the interface. As a comparison, the type-I Weyl heterostructures lack the phase transition due to the untilted band structure. This work establishes a flexible scheme of artificial Weyl heterostructures that opens a new avenue toward high-dimensional topological effects and significantly enhances our capabilities in on-chip light manipulations.
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Affiliation(s)
- Wange Song
- National Laboratory of Solid State Microstructures, Key Laboratory of Intelligent Optical Sensing and Manipulation, Jiangsu Key Laboratory of Artificial Functional Materials, College of Engineering and Applied Sciences, Nanjing University, Nanjing 210093, China
| | - Zhiyuan Lin
- National Laboratory of Solid State Microstructures, Key Laboratory of Intelligent Optical Sensing and Manipulation, Jiangsu Key Laboratory of Artificial Functional Materials, College of Engineering and Applied Sciences, Nanjing University, Nanjing 210093, China
| | - Jitao Ji
- National Laboratory of Solid State Microstructures, Key Laboratory of Intelligent Optical Sensing and Manipulation, Jiangsu Key Laboratory of Artificial Functional Materials, College of Engineering and Applied Sciences, Nanjing University, Nanjing 210093, China
| | - Jiacheng Sun
- National Laboratory of Solid State Microstructures, Key Laboratory of Intelligent Optical Sensing and Manipulation, Jiangsu Key Laboratory of Artificial Functional Materials, College of Engineering and Applied Sciences, Nanjing University, Nanjing 210093, China
| | - Chen Chen
- National Laboratory of Solid State Microstructures, Key Laboratory of Intelligent Optical Sensing and Manipulation, Jiangsu Key Laboratory of Artificial Functional Materials, College of Engineering and Applied Sciences, Nanjing University, Nanjing 210093, China
| | - Shengjie Wu
- National Laboratory of Solid State Microstructures, Key Laboratory of Intelligent Optical Sensing and Manipulation, Jiangsu Key Laboratory of Artificial Functional Materials, College of Engineering and Applied Sciences, Nanjing University, Nanjing 210093, China
| | - Chunyu Huang
- National Laboratory of Solid State Microstructures, Key Laboratory of Intelligent Optical Sensing and Manipulation, Jiangsu Key Laboratory of Artificial Functional Materials, College of Engineering and Applied Sciences, Nanjing University, Nanjing 210093, China
| | - Luqi Yuan
- State Key Laboratory of Advanced Optical Communication Systems and Networks, School of Physics and Astronomy, Shanghai Jiao Tong University, Shanghai 200240, China
| | - Shining Zhu
- National Laboratory of Solid State Microstructures, Key Laboratory of Intelligent Optical Sensing and Manipulation, Jiangsu Key Laboratory of Artificial Functional Materials, College of Engineering and Applied Sciences, Nanjing University, Nanjing 210093, China
| | - Tao Li
- National Laboratory of Solid State Microstructures, Key Laboratory of Intelligent Optical Sensing and Manipulation, Jiangsu Key Laboratory of Artificial Functional Materials, College of Engineering and Applied Sciences, Nanjing University, Nanjing 210093, China
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24
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Goyal G, Singh DK. Antiferromagnetically ordered topological semimetals in Hubbard model with spin-orbit coupling. JOURNAL OF PHYSICS. CONDENSED MATTER : AN INSTITUTE OF PHYSICS JOURNAL 2024; 36:265802. [PMID: 38527369 DOI: 10.1088/1361-648x/ad3792] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 01/07/2024] [Accepted: 03/25/2024] [Indexed: 03/27/2024]
Abstract
We examine the possible existence of Dirac semimetal with magnetic order in a two-dimensional system with a nonsymmorphic symmetry by using the Hartree-Fock mean-field theory within the Hubbard model. We locate the region in the second-neighbor spin-orbit coupling vs Hubbard interaction phase diagram, where such a state is stabilized. The edge states for the ribbons along two orthogonal directions concerning the orientation of in-plane magnetic moments are obtained. Finally, the effect of the in-plane magnetic field, which results in the stabilization of the Weyl semimetallic (WSM) state, and the nature of the edge states corresponding to the WSM state for ribbon geometries are also explored.
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Affiliation(s)
- Garima Goyal
- Department of Physics and Materials Science, Thapar Institute of Engineering and Technology, Patiala 147004, Punjab, India
| | - Dheeraj Kumar Singh
- Department of Physics and Materials Science, Thapar Institute of Engineering and Technology, Patiala 147004, Punjab, India
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25
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Zhang KX, Ju H, Kim H, Cui J, Keum J, Park JG, Lee JS. Broken Inversion Symmetry in Van Der Waals Topological Ferromagnetic Metal Iron Germanium Telluride. ADVANCED MATERIALS (DEERFIELD BEACH, FLA.) 2024; 36:e2312824. [PMID: 38161222 DOI: 10.1002/adma.202312824] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 11/28/2023] [Indexed: 01/03/2024]
Abstract
Inversion symmetry breaking is critical for many quantum effects and fundamental for spin-orbit torque, which is crucial for next-generation spintronics. Recently, a novel type of gigantic intrinsic spin-orbit torque is established in the topological van der Waals (vdW) magnet iron germanium telluride. However, it remains a puzzle because no clear evidence exists for interlayer inversion symmetry breaking. Here, the definitive evidence of broken inversion symmetry in iron germanium telluride directly measured by the second harmonic generation (SHG) technique is reported. The data show that the crystal symmetry reduces from centrosymmetric P63/mmc to noncentrosymmetric polar P3m1 space group, giving the threefold SHG pattern with dominant out-of-plane polarization. Additionally, the SHG response evolves from an isotropic pattern to a sharp threefold symmetry upon increasing Fe deficiency, mainly due to the transition from random defects to ordered Fe vacancies. Such SHG response is robust against temperature, ensuring unaltered crystalline symmetries above and below the ferromagnetic transition temperature. These findings add crucial new information to the understanding of this interesting vdW metal, iron germanium telluride: band topology, intrinsic spin-orbit torque, and topological vdW polar metal states.
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Affiliation(s)
- Kai-Xuan Zhang
- Department of Physics and Astronomy, Seoul National University, Seoul, 08826, South Korea
- Center for Quantum Materials, Department of Physics and Astronomy, Seoul National University, Seoul, 08826, South Korea
- Institute of Applied Physics, Seoul National University, Seoul, 08826, South Korea
| | - Hwiin Ju
- Department of Physics and Photon Science, Gwangju Institute of Science and Technology (GIST), Gwangju, 61005, South Korea
| | - Hyuncheol Kim
- Department of Physics and Astronomy, Seoul National University, Seoul, 08826, South Korea
- Center for Quantum Materials, Department of Physics and Astronomy, Seoul National University, Seoul, 08826, South Korea
| | - Jingyuan Cui
- Department of Physics and Astronomy, Seoul National University, Seoul, 08826, South Korea
- Center for Quantum Materials, Department of Physics and Astronomy, Seoul National University, Seoul, 08826, South Korea
| | - Jihoon Keum
- Department of Physics and Astronomy, Seoul National University, Seoul, 08826, South Korea
- Center for Quantum Materials, Department of Physics and Astronomy, Seoul National University, Seoul, 08826, South Korea
| | - Je-Geun Park
- Department of Physics and Astronomy, Seoul National University, Seoul, 08826, South Korea
- Center for Quantum Materials, Department of Physics and Astronomy, Seoul National University, Seoul, 08826, South Korea
- Institute of Applied Physics, Seoul National University, Seoul, 08826, South Korea
| | - Jong Seok Lee
- Department of Physics and Photon Science, Gwangju Institute of Science and Technology (GIST), Gwangju, 61005, South Korea
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26
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Yuan M, Qiu Y, Gao H, Feng J, Jiang L, Wu Y. Molecular Electronics: From Nanostructure Assembly to Device Integration. J Am Chem Soc 2024; 146:7885-7904. [PMID: 38483827 DOI: 10.1021/jacs.3c14044] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 03/28/2024]
Abstract
Integrated electronics and optoelectronics based on organic semiconductors have attracted considerable interest in displays, photovoltaics, and biosensing owing to their designable electronic properties, solution processability, and flexibility. Miniaturization and integration of devices are growing trends in molecular electronics and optoelectronics for practical applications, which requires large-scale and versatile assembly strategies for patterning organic micro/nano-structures with simultaneously long-range order, pure orientation, and high resolution. Although various integration methods have been developed in past decades, molecular electronics still needs a versatile platform to avoid defects and disorders due to weak intermolecular interactions in organic materials. In this perspective, a roadmap of organic integration technologies in recent three decades is provided to review the history of molecular electronics. First, we highlight the importance of long-range-ordered molecular packing for achieving exotic electronic and photophysical properties. Second, we classify the strategies for large-scale integration of molecular electronics through the control of nucleation and crystallographic orientation, and evaluate them based on factors of resolution, crystallinity, orientation, scalability, and versatility. Third, we discuss the multifunctional devices and integrated circuits based on organic field-effect transistors (OFETs) and photodetectors. Finally, we explore future research directions and outlines the need for further development of molecular electronics, including assembly of doped organic semiconductors and heterostructures, biological interfaces in molecular electronics and integrated organic logics based on complementary FETs.
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Affiliation(s)
- Meng Yuan
- Key Laboratory of Bio-inspired Materials and Interfacial Science, Technical Institute of Physics and Chemistry, Chinese Academy of Sciences, Beijing 100190, P. R. China
- University of Chinese Academy of Sciences (UCAS), Beijing 100049, P. R. China
| | - Yuchen Qiu
- State Key Laboratory of Supramolecular Structure and Materials, College of Chemistry, Jilin University, Changchun 130012, P. R. China
| | - Hanfei Gao
- Suzhou Institute for Advanced Research, University of Science and Technology of China, Suzhou 215123, P. R. China
| | - Jiangang Feng
- Department of Electrical and Computer Engineering, National University of Singapore, Singapore 117583, Singapore
| | - Lei Jiang
- Key Laboratory of Bio-inspired Materials and Interfacial Science, Technical Institute of Physics and Chemistry, Chinese Academy of Sciences, Beijing 100190, P. R. China
| | - Yuchen Wu
- Key Laboratory of Bio-inspired Materials and Interfacial Science, Technical Institute of Physics and Chemistry, Chinese Academy of Sciences, Beijing 100190, P. R. China
- University of Chinese Academy of Sciences (UCAS), Beijing 100049, P. R. China
- Key Laboratory for Special Functional Materials of Ministry of Education, National and Local Joint Engineering Research Center for High-Efficiency Display and Lighting Technology, Collaborative Innovation Center of Nano Functional Materials and Applications, Henan University, Kaifeng 475004, P. R. China
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27
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Park H, Oh SS, Lee S. Surface potential-adjusted surface states in 3D topological photonic crystals. Sci Rep 2024; 14:7173. [PMID: 38531983 DOI: 10.1038/s41598-024-56894-6] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/21/2024] [Accepted: 03/12/2024] [Indexed: 03/28/2024] Open
Abstract
Surface potential in a topological matter could unprecedentedly localize the waves. However, this surface potential is yet to be exploited in topological photonic systems. Here, we demonstrate that photonic surface states can be induced and controlled by the surface potential in a dielectric double gyroid (DG) photonic crystal. The basis translation in a unit cell enables tuning of the surface potential, which in turn regulates the degree of wave localization. The gradual modulation of DG photonic crystals enables the generation of a pseudomagnetic field. Overall, this study shows the interplay between surface potential and pseudomagnetic field regarding the surface states. The physical consequences outlined herein not only widen the scope of surface states in 3D photonic crystals but also highlight the importance of surface treatments in a photonic system.
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Affiliation(s)
- Haedong Park
- KU-KIST Graduate School of Converging Science and Technology, Korea University, Seoul, 02841, Republic of Korea.
- School of Physics and Astronomy, Cardiff University, Cardiff, CF24 3AA, UK.
| | - Sang Soon Oh
- School of Physics and Astronomy, Cardiff University, Cardiff, CF24 3AA, UK.
| | - Seungwoo Lee
- KU-KIST Graduate School of Converging Science and Technology, Korea University, Seoul, 02841, Republic of Korea.
- Department of Biomicrosystem Technology, Korea University, Seoul, 02841, Republic of Korea.
- Department of Integrative Energy Engineering and KU Photonics Center, Korea University, Seoul, 02841, Republic of Korea.
- Center for Opto-Electronic Materials and Devices, Post-Silicon Semiconductor Institute, Korea Institute of Science and Technology (KIST), Seoul, 02792, Republic of Korea.
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28
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Zhang XX, Nagaosa N. Surface spectroscopy and surface-bulk hybridization of Weyl semimetals. Proc Natl Acad Sci U S A 2024; 121:e2313488121. [PMID: 38513104 PMCID: PMC10990132 DOI: 10.1073/pnas.2313488121] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/05/2023] [Accepted: 01/30/2024] [Indexed: 03/23/2024] Open
Abstract
Weyl semimetal showing open-arc surface states is a prominent example of topological quantum matter in three dimensions. With the bulk-boundary correspondence present, nontrivial surface-bulk hybridization is inevitable but less understood. Spectroscopies have been often limited to verifying the existence of surface Fermi arcs, whereas its spectral shape related to the hybridization profile in energy-momentum space is not well studied. We present an exactly solvable formalism at the surface for a wide range of prototypical Weyl semimetals. The resonant surface state and the bulk influence coexist as a surface-bulk hybrid and are treated in a unified manner. Directly accessible to angle-resolved photoemission spectroscopy, we analytically reveal universal information about the system obtained from the spectroscopy of resonant topological states. We systematically find inhomogeneous and anisotropic singular responses around the surface-bulk merging borderline crossing Weyl points, highlighting its critical role in the Weyl topology. The response in scanning tunneling spectroscopy is also discussed. The results will provide much-needed insight into the surface-bulk-coupled physical properties and guide in-depth spectroscopic investigation of the nontrivial hybrid in many topological semimetal materials.
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Affiliation(s)
- Xiao-Xiao Zhang
- Wuhan National High Magnetic Field Center and School of Physics, Huazhong University of Science and Technology, Wuhan430074, China
- RIKEN Center for Emergent Matter Science (CEMS), Saitama351-0198, Japan
| | - Naoto Nagaosa
- RIKEN Center for Emergent Matter Science (CEMS), Saitama351-0198, Japan
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29
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Tian Q, Bagheri Tagani M, Izadi Vishkayi S, Zhang C, Li B, Zhang L, Yin LJ, Tian Y, Zhang L, Qin Z. Twist-Angle Tuning of Electronic Structure in Two-Dimensional Dirac Nodal Line Semimetal Au 2Ge on Au(111). ACS NANO 2024; 18:9011-9018. [PMID: 38470156 DOI: 10.1021/acsnano.3c12753] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 03/13/2024]
Abstract
Topological semimetals have emerged as quantum materials including Dirac, Weyl, and nodal line semimetals, and so on. Dirac nodal line (DNL) semimetals possess topologically nontrivial bands crossing along a line or a loop and are considered precursor states for other types of semimetals. Here, we combine scanning tunneling microscopy/spectroscopy (STM/S) measurements and density functional theory (DFT) calculations to investigate a twist angle tuning of electronic structure in two-dimensional DNL semimetal Au2Ge. Theoretical calculations show that two bands of Au2Ge touch each other in Γ-M and Γ-K paths, forming a DNL. A significant transition of electronic structure occurs by tuning the twist angle from 30° to 24° between monolayer Au2Ge and Au(111), as confirmed by STS measurements and DFT calculations. The disappearing of DNL state is a direct consequence of symmetry breaking.
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Affiliation(s)
- Qiwei Tian
- Key Laboratory for Micro/Nano Optoelectronic Devices of Ministry of Education & Hunan Provincial Key Laboratory of Low-Dimensional Structural Physics and Devices, School of Physics and Electronics, Hunan University, Changsha 410082, China
| | - Meysam Bagheri Tagani
- Department of Physics, University of Guilan, P.O. Box 41335-1914, 32504550, Rasht, Iran
| | - Sahar Izadi Vishkayi
- School of Physics, Institute for Research in Fundamental Sciences (IPM), P.O. Box 19395-5531, Tehran, Iran
| | - Chen Zhang
- Key Laboratory for Micro/Nano Optoelectronic Devices of Ministry of Education & Hunan Provincial Key Laboratory of Low-Dimensional Structural Physics and Devices, School of Physics and Electronics, Hunan University, Changsha 410082, China
| | - Bo Li
- Key Laboratory for Micro/Nano Optoelectronic Devices of Ministry of Education & Hunan Provincial Key Laboratory of Low-Dimensional Structural Physics and Devices, School of Physics and Electronics, Hunan University, Changsha 410082, China
| | - Li Zhang
- Key Laboratory for Micro/Nano Optoelectronic Devices of Ministry of Education & Hunan Provincial Key Laboratory of Low-Dimensional Structural Physics and Devices, School of Physics and Electronics, Hunan University, Changsha 410082, China
| | - Long-Jing Yin
- Key Laboratory for Micro/Nano Optoelectronic Devices of Ministry of Education & Hunan Provincial Key Laboratory of Low-Dimensional Structural Physics and Devices, School of Physics and Electronics, Hunan University, Changsha 410082, China
| | - Yuan Tian
- Key Laboratory for Micro/Nano Optoelectronic Devices of Ministry of Education & Hunan Provincial Key Laboratory of Low-Dimensional Structural Physics and Devices, School of Physics and Electronics, Hunan University, Changsha 410082, China
| | - Lijie Zhang
- Key Laboratory for Micro/Nano Optoelectronic Devices of Ministry of Education & Hunan Provincial Key Laboratory of Low-Dimensional Structural Physics and Devices, School of Physics and Electronics, Hunan University, Changsha 410082, China
| | - Zhihui Qin
- Key Laboratory for Micro/Nano Optoelectronic Devices of Ministry of Education & Hunan Provincial Key Laboratory of Low-Dimensional Structural Physics and Devices, School of Physics and Electronics, Hunan University, Changsha 410082, China
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30
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Tian M, Velkovsky I, Chen T, Sun F, He Q, Gadway B. Manipulation of Weyl Points in Reciprocal and Nonreciprocal Mechanical Lattices. PHYSICAL REVIEW LETTERS 2024; 132:126602. [PMID: 38579212 DOI: 10.1103/physrevlett.132.126602] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 08/22/2023] [Accepted: 02/22/2024] [Indexed: 04/07/2024]
Abstract
We introduce feedback-measurement technologies to achieve flexible control of Weyl points and conduct the first experimental demonstration of Weyl type I-II transition in mechanical systems. We demonstrate that non-Hermiticity can expand the Fermi arc surface states from connecting Weyl points to Weyl rings, and lead to a localization transition of edge states influenced by the interplay between band topology and the non-Hermitian skin effect. Our findings offer valuable insights into the design and manipulation of Weyl points in mechanical systems, providing a promising avenue for manipulating topological modes in non-Hermitian systems.
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Affiliation(s)
- Mingsheng Tian
- State Key Laboratory for Mesoscopic Physics, School of Physics, Frontiers Science Center for Nano-optoelectronics, & Collaborative Innovation Center of Quantum Matter, Peking University, Beijing 100871, China
- Department of Physics, University of Illinois at Urbana-Champaign, Urbana, Illinois 61801-3080, USA
| | - Ivan Velkovsky
- Department of Physics, University of Illinois at Urbana-Champaign, Urbana, Illinois 61801-3080, USA
| | - Tao Chen
- Department of Physics, University of Illinois at Urbana-Champaign, Urbana, Illinois 61801-3080, USA
| | - Fengxiao Sun
- State Key Laboratory for Mesoscopic Physics, School of Physics, Frontiers Science Center for Nano-optoelectronics, & Collaborative Innovation Center of Quantum Matter, Peking University, Beijing 100871, China
| | - Qiongyi He
- State Key Laboratory for Mesoscopic Physics, School of Physics, Frontiers Science Center for Nano-optoelectronics, & Collaborative Innovation Center of Quantum Matter, Peking University, Beijing 100871, China
- Collaborative Innovation Center of Extreme Optics, Shanxi University, Taiyuan 030006, China
- Hefei National Laboratory, Hefei, 230088, China
| | - Bryce Gadway
- Department of Physics, University of Illinois at Urbana-Champaign, Urbana, Illinois 61801-3080, USA
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31
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Lu X, Lin Z, Pi H, Zhang T, Li G, Gong Y, Yan Y, Ruan X, Li Y, Zhang H, Li L, He L, Wu J, Zhang R, Weng H, Zeng C, Xu Y. Ultrafast magnetization enhancement via the dynamic spin-filter effect of type-II Weyl nodes in a kagome ferromagnet. Nat Commun 2024; 15:2410. [PMID: 38499551 PMCID: PMC10948858 DOI: 10.1038/s41467-024-46604-1] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/17/2023] [Accepted: 02/21/2024] [Indexed: 03/20/2024] Open
Abstract
The magnetic type-II Weyl semimetal (MWSM) Co3Sn2S2 has recently been found to host a variety of remarkable phenomena including surface Fermi-arcs, giant anomalous Hall effect, and negative flat band magnetism. However, the dynamic magnetic properties remain relatively unexplored. Here, we investigate the ultrafast spin dynamics of Co3Sn2S2 crystal using time-resolved magneto-optical Kerr effect and reflectivity spectroscopies. We observe a transient magnetization behavior, consisting of spin-flipping dominated fast demagnetization, slow demagnetization due to overall half-metallic electronic structures, and an unexpected ultrafast magnetization enhancement lasting hundreds of picoseconds upon femtosecond laser excitation. By combining temperature-, pump fluence-, and pump polarization-dependent measurements, we unambiguously demonstrate the correlation between the ultrafast magnetization enhancement and the Weyl nodes. Our theoretical modelling suggests that the excited electrons are spin-polarized when relaxing, leading to the enhanced spin-up density of states near the Fermi level and the consequently unusual magnetization enhancement. Our results reveal the unique role of the Weyl properties of Co3Sn2S2 in femtosecond laser-induced spin dynamics.
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Affiliation(s)
- Xianyang Lu
- School of Integrated Circuits, Nanjing University, Suzhou, 215163, China
- State Key Laboratory of Spintronics Devices and Technologies, Nanjing University, Suzhou, 215163, China
- Jiangsu Provincial Key Laboratory of Advanced Photonic and Electronic Materials, School of Electronic Science and Engineering, Nanjing University, Nanjing, 210093, China
| | - Zhiyong Lin
- International Center for Quantum Design of Functional Materials (ICQD), Hefei National Laboratory for Physical Sciences at the Microscale, and Synergetic Innovation Center of Quantum Information and Quantum Physics, University of Science and Technology of China, Hefei, Anhui, 230026, China
- CAS Key Laboratory of Strongly-Coupled Quantum Matter Physics, and Department of Physics, University of Science and Technology of China, Hefei, Anhui, 230026, China
| | - Hanqi Pi
- Beijing National Research Center for Condensed Matter Physics, Institute of Physics, Chinese Academy of Sciences, Beijing, 100190, China
- School of Physical Science, University of Chinese Academy of Sciences, Beijing, 100049, China
- Songshan Lake Materials Laboratory, Dongguan, Guangdong, 523808, China
| | - Tan Zhang
- Department of Chemistry, University of Pennsylvania, Philadelphia, PA, 19104-6323, USA
| | - Guanqi Li
- School of Integrated Circuits, Guangdong University of Technology, Guangzhou, 510006, China
| | - Yuting Gong
- State Key Laboratory of Spintronics Devices and Technologies, Nanjing University, Suzhou, 215163, China
- Jiangsu Provincial Key Laboratory of Advanced Photonic and Electronic Materials, School of Electronic Science and Engineering, Nanjing University, Nanjing, 210093, China
| | - Yu Yan
- State Key Laboratory of Spintronics Devices and Technologies, Nanjing University, Suzhou, 215163, China
- Jiangsu Provincial Key Laboratory of Advanced Photonic and Electronic Materials, School of Electronic Science and Engineering, Nanjing University, Nanjing, 210093, China
| | - Xuezhong Ruan
- State Key Laboratory of Spintronics Devices and Technologies, Nanjing University, Suzhou, 215163, China
- Jiangsu Provincial Key Laboratory of Advanced Photonic and Electronic Materials, School of Electronic Science and Engineering, Nanjing University, Nanjing, 210093, China
| | - Yao Li
- State Key Laboratory of Spintronics Devices and Technologies, Nanjing University, Suzhou, 215163, China
- Jiangsu Provincial Key Laboratory of Advanced Photonic and Electronic Materials, School of Electronic Science and Engineering, Nanjing University, Nanjing, 210093, China
| | - Hui Zhang
- International Center for Quantum Design of Functional Materials (ICQD), Hefei National Laboratory for Physical Sciences at the Microscale, and Synergetic Innovation Center of Quantum Information and Quantum Physics, University of Science and Technology of China, Hefei, Anhui, 230026, China
- CAS Key Laboratory of Strongly-Coupled Quantum Matter Physics, and Department of Physics, University of Science and Technology of China, Hefei, Anhui, 230026, China
| | - Lin Li
- International Center for Quantum Design of Functional Materials (ICQD), Hefei National Laboratory for Physical Sciences at the Microscale, and Synergetic Innovation Center of Quantum Information and Quantum Physics, University of Science and Technology of China, Hefei, Anhui, 230026, China
- CAS Key Laboratory of Strongly-Coupled Quantum Matter Physics, and Department of Physics, University of Science and Technology of China, Hefei, Anhui, 230026, China
| | - Liang He
- State Key Laboratory of Spintronics Devices and Technologies, Nanjing University, Suzhou, 215163, China
- Jiangsu Provincial Key Laboratory of Advanced Photonic and Electronic Materials, School of Electronic Science and Engineering, Nanjing University, Nanjing, 210093, China
| | - Jing Wu
- School of Integrated Circuits, Guangdong University of Technology, Guangzhou, 510006, China.
- York-Nanjing International Joint Center in Spintronics, School of Physics, Engineering and Technology, University of York, York, YO10 5DD, UK.
| | - Rong Zhang
- Jiangsu Provincial Key Laboratory of Advanced Photonic and Electronic Materials, School of Electronic Science and Engineering, Nanjing University, Nanjing, 210093, China
| | - Hongming Weng
- Beijing National Research Center for Condensed Matter Physics, Institute of Physics, Chinese Academy of Sciences, Beijing, 100190, China.
- School of Physical Science, University of Chinese Academy of Sciences, Beijing, 100049, China.
- Songshan Lake Materials Laboratory, Dongguan, Guangdong, 523808, China.
| | - Changgan Zeng
- International Center for Quantum Design of Functional Materials (ICQD), Hefei National Laboratory for Physical Sciences at the Microscale, and Synergetic Innovation Center of Quantum Information and Quantum Physics, University of Science and Technology of China, Hefei, Anhui, 230026, China.
- CAS Key Laboratory of Strongly-Coupled Quantum Matter Physics, and Department of Physics, University of Science and Technology of China, Hefei, Anhui, 230026, China.
| | - Yongbing Xu
- School of Integrated Circuits, Nanjing University, Suzhou, 215163, China.
- State Key Laboratory of Spintronics Devices and Technologies, Nanjing University, Suzhou, 215163, China.
- Jiangsu Provincial Key Laboratory of Advanced Photonic and Electronic Materials, School of Electronic Science and Engineering, Nanjing University, Nanjing, 210093, China.
- York-Nanjing International Joint Center in Spintronics, School of Physics, Engineering and Technology, University of York, York, YO10 5DD, UK.
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Ma J, Jia D, Zhang L, Guan YJ, Ge Y, Sun HX, Yuan SQ, Chen H, Yang Y, Zhang X. Observation of vortex-string chiral modes in metamaterials. Nat Commun 2024; 15:2332. [PMID: 38485983 PMCID: PMC10940314 DOI: 10.1038/s41467-024-46641-w] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/07/2023] [Accepted: 03/05/2024] [Indexed: 03/18/2024] Open
Abstract
As hypothetical topological defects in the geometry of spacetime, vortex strings could have played many roles in cosmology, and their distinct features can provide observable clues about the early universe's evolution. A key feature of vortex strings is that they can interact with Weyl fermionic modes and support massless chiral-anomaly states along strings. To date, despite many attempts to detect vortex strings in astrophysics or to emulate them in artificially created systems, observation of these vortex-string chiral modes remains experimentally elusive. Here we report experimental observations of vortex-string chiral modes using a metamaterial system. This is implemented by inhomogeneous perturbation of Yang-monopole phononic metamaterials. The measured linear dispersion and modal profiles confirm the existence of topological modes bound to and propagating along the string with the chiral anomaly. Our work provides a platform for studying diverse cosmic topological defects in astrophysics and offers applications as topological fibres in communication techniques.
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Affiliation(s)
- Jingwen Ma
- Faculties of Science and Engineering, The University of Hong Kong, Hong Kong, China
| | - Ding Jia
- Interdisciplinary Center for Quantum Information, State Key Laboratory of Extreme Photonics and Instrumentation, ZJU-Hangzhou Global Scientific and Technological Innovation Center, Zhejiang University, Hangzhou, 310027, China
- Research Center of Fluid Machinery Engineering and Technology, School of Physics and Electronic Engineering, Jiangsu University, Zhenjiang, 212013, China
| | - Li Zhang
- Interdisciplinary Center for Quantum Information, State Key Laboratory of Extreme Photonics and Instrumentation, ZJU-Hangzhou Global Scientific and Technological Innovation Center, Zhejiang University, Hangzhou, 310027, China
- International Joint Innovation Center, The Electromagnetics Academy at Zhejiang University, Zhejiang University, Haining, 314400, China
- Key Laboratory of Advanced Micro/Nano Electronic Devices & Smart Systems of Zhejiang, Jinhua Institute of Zhejiang University, Zhejiang University, Jinhua, 321099, China
- Shaoxing Institute of Zhejiang University, Zhejiang University, Shaoxing, 312000, China
| | - Yi-Jun Guan
- Research Center of Fluid Machinery Engineering and Technology, School of Physics and Electronic Engineering, Jiangsu University, Zhenjiang, 212013, China
| | - Yong Ge
- Research Center of Fluid Machinery Engineering and Technology, School of Physics and Electronic Engineering, Jiangsu University, Zhenjiang, 212013, China
| | - Hong-Xiang Sun
- Research Center of Fluid Machinery Engineering and Technology, School of Physics and Electronic Engineering, Jiangsu University, Zhenjiang, 212013, China.
- State Key Laboratory of Acoustics, Institute of Acoustics, Chinese Academy of Sciences, Beijing, 100190, China.
| | - Shou-Qi Yuan
- Research Center of Fluid Machinery Engineering and Technology, School of Physics and Electronic Engineering, Jiangsu University, Zhenjiang, 212013, China
| | - Hongsheng Chen
- Interdisciplinary Center for Quantum Information, State Key Laboratory of Extreme Photonics and Instrumentation, ZJU-Hangzhou Global Scientific and Technological Innovation Center, Zhejiang University, Hangzhou, 310027, China
- International Joint Innovation Center, The Electromagnetics Academy at Zhejiang University, Zhejiang University, Haining, 314400, China
- Key Laboratory of Advanced Micro/Nano Electronic Devices & Smart Systems of Zhejiang, Jinhua Institute of Zhejiang University, Zhejiang University, Jinhua, 321099, China
- Shaoxing Institute of Zhejiang University, Zhejiang University, Shaoxing, 312000, China
| | - Yihao Yang
- Interdisciplinary Center for Quantum Information, State Key Laboratory of Extreme Photonics and Instrumentation, ZJU-Hangzhou Global Scientific and Technological Innovation Center, Zhejiang University, Hangzhou, 310027, China.
- International Joint Innovation Center, The Electromagnetics Academy at Zhejiang University, Zhejiang University, Haining, 314400, China.
- Key Laboratory of Advanced Micro/Nano Electronic Devices & Smart Systems of Zhejiang, Jinhua Institute of Zhejiang University, Zhejiang University, Jinhua, 321099, China.
- Shaoxing Institute of Zhejiang University, Zhejiang University, Shaoxing, 312000, China.
| | - Xiang Zhang
- Faculties of Science and Engineering, The University of Hong Kong, Hong Kong, China.
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Wu W, Shi Z, Ozerov M, Du Y, Wang Y, Ni XS, Meng X, Jiang X, Wang G, Hao C, Wang X, Zhang P, Pan C, Pan H, Sun Z, Yang R, Xu Y, Hou Y, Yan Z, Zhang C, Lu HZ, Chu J, Yuan X. The discovery of three-dimensional Van Hove singularity. Nat Commun 2024; 15:2313. [PMID: 38485978 PMCID: PMC10940667 DOI: 10.1038/s41467-024-46626-9] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/04/2023] [Accepted: 02/29/2024] [Indexed: 03/18/2024] Open
Abstract
Arising from the extreme/saddle point in electronic bands, Van Hove singularity (VHS) manifests divergent density of states (DOS) and induces various new states of matter such as unconventional superconductivity. VHS is believed to exist in one and two dimensions, but rarely found in three dimension (3D). Here, we report the discovery of 3D VHS in a topological magnet EuCd2As2 by magneto-infrared spectroscopy. External magnetic fields effectively control the exchange interaction in EuCd2As2, and shift 3D Weyl bands continuously, leading to the modification of Fermi velocity and energy dispersion. Above the critical field, the 3D VHS forms and is evidenced by the abrupt emergence of inter-band transitions, which can be quantitatively described by the minimal model of Weyl semimetals. Three additional optical transitions are further predicted theoretically and verified in magneto-near-infrared spectra. Our results pave the way to exploring VHS in 3D systems and uncovering the coordination between electronic correlation and the topological phase.
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Affiliation(s)
- Wenbin Wu
- State Key Laboratory of Precision Spectroscopy, East China Normal University, 200241, Shanghai, China
- Key Laboratory of Polar Materials and Devices, Ministry of Education, School of Physics and Electronic Science, East China Normal University, 200241, Shanghai, China
- Shanghai Center of Brain-Inspired Intelligent Materials and Devices, East China Normal University, 200241, Shanghai, China
| | - Zeping Shi
- State Key Laboratory of Precision Spectroscopy, East China Normal University, 200241, Shanghai, China
| | - Mykhaylo Ozerov
- National High Magnetic Field Laboratory, Florida State University, Tallahassee, FL, 32310, USA
| | - Yuhan Du
- State Key Laboratory of Precision Spectroscopy, East China Normal University, 200241, Shanghai, China
| | - Yuxiang Wang
- State Key Laboratory of Surface Physics and Institute for Nanoelectronic Devices and Quantum Computing, Fudan University, 200433, Shanghai, China
| | - Xiao-Sheng Ni
- Guangdong Provincial Key Laboratory of Magnetoelectric Physics and Devices, School of Physics, Sun Yat-Sen University, 510275, Guangzhou, China
| | - Xianghao Meng
- State Key Laboratory of Precision Spectroscopy, East China Normal University, 200241, Shanghai, China
| | - Xiangyu Jiang
- State Key Laboratory of Precision Spectroscopy, East China Normal University, 200241, Shanghai, China
| | - Guangyi Wang
- State Key Laboratory of Precision Spectroscopy, East China Normal University, 200241, Shanghai, China
| | - Congming Hao
- State Key Laboratory of Precision Spectroscopy, East China Normal University, 200241, Shanghai, China
| | - Xinyi Wang
- State Key Laboratory of Precision Spectroscopy, East China Normal University, 200241, Shanghai, China
| | - Pengcheng Zhang
- State Key Laboratory of Precision Spectroscopy, East China Normal University, 200241, Shanghai, China
| | - Chunhui Pan
- Multifunctional Platform for Innovation Precision Machining Center, East China Normal University, 200241, Shanghai, China
| | - Haifeng Pan
- State Key Laboratory of Precision Spectroscopy, East China Normal University, 200241, Shanghai, China
| | - Zhenrong Sun
- State Key Laboratory of Precision Spectroscopy, East China Normal University, 200241, Shanghai, China
| | - Run Yang
- Key Laboratory of Quantum Materials and Devices of Ministry of Education, School of Physics, Southeast University, 211189, Nanjing, China
| | - Yang Xu
- Key Laboratory of Polar Materials and Devices, Ministry of Education, School of Physics and Electronic Science, East China Normal University, 200241, Shanghai, China
| | - Yusheng Hou
- Guangdong Provincial Key Laboratory of Magnetoelectric Physics and Devices, School of Physics, Sun Yat-Sen University, 510275, Guangzhou, China
| | - Zhongbo Yan
- Guangdong Provincial Key Laboratory of Magnetoelectric Physics and Devices, School of Physics, Sun Yat-Sen University, 510275, Guangzhou, China
| | - Cheng Zhang
- State Key Laboratory of Surface Physics and Institute for Nanoelectronic Devices and Quantum Computing, Fudan University, 200433, Shanghai, China
- Zhangjiang Fudan International Innovation Center, Fudan University, 201210, Shanghai, China
| | - Hai-Zhou Lu
- Shenzhen Institute for Quantum Science and Engineering and Department of Physics, Southern University of Science and Technology (SUSTech), 518055, Shenzhen, China
| | - Junhao Chu
- Key Laboratory of Polar Materials and Devices, Ministry of Education, School of Physics and Electronic Science, East China Normal University, 200241, Shanghai, China
- Institute of Optoelectronics, Fudan University, 200438, Shanghai, China
| | - Xiang Yuan
- State Key Laboratory of Precision Spectroscopy, East China Normal University, 200241, Shanghai, China.
- Key Laboratory of Polar Materials and Devices, Ministry of Education, School of Physics and Electronic Science, East China Normal University, 200241, Shanghai, China.
- Shanghai Center of Brain-Inspired Intelligent Materials and Devices, East China Normal University, 200241, Shanghai, China.
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34
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Kong X, Liu Z, Geng Z, Zhang A, Guo Z, Cui S, Xia C, Tan S, Zhou S, Wang Z, Zeng J. Experimental Demonstration of Topological Catalysis for CO 2 Electroreduction. J Am Chem Soc 2024; 146:6536-6543. [PMID: 38412553 DOI: 10.1021/jacs.3c11088] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/29/2024]
Abstract
The past decade has witnessed substantial progress in understanding nontrivial band topology and discovering exotic topological materials in condensed-matter physics. Recently, topological physics has been further extended to the chemistry discipline, leading to the emergence of topological catalysis. In principle, the topological effect is detectable in catalytic reactions, but no conclusive evidence has been reported yet. Herein, by precisely manipulating the topological surface state (TSS) of Bi2Se3 nanosheets through thickness control and the application of a magnetic field, we provide direct experimental evidence to illustrate topological catalysis for CO2 electroreduction. With and without the cooperation of TSS, CO2 is mainly reduced into liquid fuels (HCOOH and H2C2O4) and CO, exhibiting high (up to 90% at -1.1 V versus reversible hydrogen electrode) and low Faradaic efficiency (FE), respectively. Theoretically, the product and FE difference can be attributed to the TSS-regulated adsorption of key intermediates and the reduced barrier of the potential-determining step. Our work demonstrates the inherent correlation between band topology and electrocatalysis, paving a new avenue for designing high-performance catalysts.
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Affiliation(s)
- Xiangdong Kong
- Hefei National Research Center for Physical Sciences at the Microscale, Key Laboratory of Strongly-Coupled Quantum Matter Physics of Chinese Academy of Sciences, Key Laboratory of Surface and Interface Chemistry and Energy Catalysis of Anhui Higher Education Institutes, Department of Chemical Physics, Hefei National Laboratory, University of Science and Technology of China, Hefei, Anhui 230026, P. R. China
| | - Zhao Liu
- Hefei National Research Center for Physical Sciences at the Microscale, Key Laboratory of Strongly-Coupled Quantum Matter Physics of Chinese Academy of Sciences, Key Laboratory of Surface and Interface Chemistry and Energy Catalysis of Anhui Higher Education Institutes, Department of Chemical Physics, Hefei National Laboratory, University of Science and Technology of China, Hefei, Anhui 230026, P. R. China
| | - Zhigang Geng
- Hefei National Research Center for Physical Sciences at the Microscale, Key Laboratory of Strongly-Coupled Quantum Matter Physics of Chinese Academy of Sciences, Key Laboratory of Surface and Interface Chemistry and Energy Catalysis of Anhui Higher Education Institutes, Department of Chemical Physics, Hefei National Laboratory, University of Science and Technology of China, Hefei, Anhui 230026, P. R. China
| | - An Zhang
- Hefei National Research Center for Physical Sciences at the Microscale, Key Laboratory of Strongly-Coupled Quantum Matter Physics of Chinese Academy of Sciences, Key Laboratory of Surface and Interface Chemistry and Energy Catalysis of Anhui Higher Education Institutes, Department of Chemical Physics, Hefei National Laboratory, University of Science and Technology of China, Hefei, Anhui 230026, P. R. China
| | - Ziyang Guo
- Hefei National Research Center for Physical Sciences at the Microscale, Key Laboratory of Strongly-Coupled Quantum Matter Physics of Chinese Academy of Sciences, Key Laboratory of Surface and Interface Chemistry and Energy Catalysis of Anhui Higher Education Institutes, Department of Chemical Physics, Hefei National Laboratory, University of Science and Technology of China, Hefei, Anhui 230026, P. R. China
| | - Shengtao Cui
- Hefei National Research Center for Physical Sciences at the Microscale, Key Laboratory of Strongly-Coupled Quantum Matter Physics of Chinese Academy of Sciences, Key Laboratory of Surface and Interface Chemistry and Energy Catalysis of Anhui Higher Education Institutes, Department of Chemical Physics, Hefei National Laboratory, University of Science and Technology of China, Hefei, Anhui 230026, P. R. China
| | - Chuan Xia
- School of Materials and Energy, University of Electronic Science and Technology of China, Chengdu, Sichuan 611731, P. R. China
| | - Shijing Tan
- Hefei National Research Center for Physical Sciences at the Microscale, Key Laboratory of Strongly-Coupled Quantum Matter Physics of Chinese Academy of Sciences, Key Laboratory of Surface and Interface Chemistry and Energy Catalysis of Anhui Higher Education Institutes, Department of Chemical Physics, Hefei National Laboratory, University of Science and Technology of China, Hefei, Anhui 230026, P. R. China
| | - Shiming Zhou
- Hefei National Research Center for Physical Sciences at the Microscale, Key Laboratory of Strongly-Coupled Quantum Matter Physics of Chinese Academy of Sciences, Key Laboratory of Surface and Interface Chemistry and Energy Catalysis of Anhui Higher Education Institutes, Department of Chemical Physics, Hefei National Laboratory, University of Science and Technology of China, Hefei, Anhui 230026, P. R. China
| | - Zhengfei Wang
- Hefei National Research Center for Physical Sciences at the Microscale, Key Laboratory of Strongly-Coupled Quantum Matter Physics of Chinese Academy of Sciences, Key Laboratory of Surface and Interface Chemistry and Energy Catalysis of Anhui Higher Education Institutes, Department of Chemical Physics, Hefei National Laboratory, University of Science and Technology of China, Hefei, Anhui 230026, P. R. China
| | - Jie Zeng
- Hefei National Research Center for Physical Sciences at the Microscale, Key Laboratory of Strongly-Coupled Quantum Matter Physics of Chinese Academy of Sciences, Key Laboratory of Surface and Interface Chemistry and Energy Catalysis of Anhui Higher Education Institutes, Department of Chemical Physics, Hefei National Laboratory, University of Science and Technology of China, Hefei, Anhui 230026, P. R. China
- School of Chemistry & Chemical Engineering, Anhui University of Technology, Ma'anshan, Anhui 243002, P. R. China
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35
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Ma Q, Pu Z, Ye L, Lu J, Huang X, Ke M, He H, Deng W, Liu Z. Observation of Higher-Order Nodal-Line Semimetal in Phononic Crystals. PHYSICAL REVIEW LETTERS 2024; 132:066601. [PMID: 38394560 DOI: 10.1103/physrevlett.132.066601] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/05/2023] [Accepted: 01/05/2024] [Indexed: 02/25/2024]
Abstract
Higher-order topological insulators and semimetals, which generalize the conventional bulk-boundary correspondence, have attracted extensive research interest. Among them, higher-order Weyl semimetals feature twofold linear crossing points in three-dimensional momentum space, 2D Fermi-arc surface states, and 1D hinge states. Higher-order nodal-point semimetals possessing Weyl points or Dirac points have been implemented. However, higher-order nodal-line or nodal-surface semimetals remain to be further explored in experiments in spite of many previous theoretical efforts. In this work, we realize a second-order nodal-line semimetal in 3D phononic crystals. The bulk nodal lines, 2D drumhead surface states guaranteed by Zak phases, and 1D flat hinge states attributed to k_{z}-dependent quadrupole moments are observed in simulations and experiments. Our findings of nondispersive surface and hinge states may promote applications in acoustic sensing and energy harvesting.
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Affiliation(s)
- Qiyun Ma
- Key Laboratory of Artificial Micro- and Nano-structures of Ministry of Education and School of Physics and Technology, Wuhan University, Wuhan 430072, China
| | - Zhenhang Pu
- Key Laboratory of Artificial Micro- and Nano-structures of Ministry of Education and School of Physics and Technology, Wuhan University, Wuhan 430072, China
| | - Liping Ye
- Key Laboratory of Artificial Micro- and Nano-structures of Ministry of Education and School of Physics and Technology, Wuhan University, Wuhan 430072, China
| | - Jiuyang Lu
- Key Laboratory of Artificial Micro- and Nano-structures of Ministry of Education and School of Physics and Technology, Wuhan University, Wuhan 430072, China
| | - Xueqin Huang
- School of Physics and Optoelectronics, South China University of Technology, Guangzhou 510640, China
| | - Manzhu Ke
- Key Laboratory of Artificial Micro- and Nano-structures of Ministry of Education and School of Physics and Technology, Wuhan University, Wuhan 430072, China
| | - Hailong He
- Key Laboratory of Artificial Micro- and Nano-structures of Ministry of Education and School of Physics and Technology, Wuhan University, Wuhan 430072, China
| | - Weiyin Deng
- Key Laboratory of Artificial Micro- and Nano-structures of Ministry of Education and School of Physics and Technology, Wuhan University, Wuhan 430072, China
| | - Zhengyou Liu
- Key Laboratory of Artificial Micro- and Nano-structures of Ministry of Education and School of Physics and Technology, Wuhan University, Wuhan 430072, China
- Institute for Advanced Studies, Wuhan University, Wuhan 430072, China
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36
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Lopes EVC, Baierle RJ, Miwa RH, Schmidt TM. Noncentrosymmetric two-dimensional Weyl semimetals in porous Si/Ge structures. JOURNAL OF PHYSICS. CONDENSED MATTER : AN INSTITUTE OF PHYSICS JOURNAL 2024; 36:185701. [PMID: 38215486 DOI: 10.1088/1361-648x/ad1e09] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/24/2023] [Accepted: 01/12/2024] [Indexed: 01/14/2024]
Abstract
In this work we predict a family of noncentrosymmetric two-dimensional (2D) Weyl semimetals (WSMs) composed by porous Ge and SiGe structures. These systems are energetically stable graphenylene-like structures with a buckling, spontaneously breaking the inversion symmetry. The nontrivial topological phase for these 2D systems occurs just below the Fermi level, resulting in nonvanishing Berry curvature around the Weyl nodes. The emerged WSMs are protected byC3symmetry, presenting one-dimensional edge Fermi-arcs connecting Weyl points with opposite chiralities. Our findings complete the family of Weyl in condensed-matter physics, by predicting the first noncentrosymmetric class of 2D WSMs.
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Affiliation(s)
- Emmanuel V C Lopes
- Instituto de Física, Universidade Federal de Uberlândia, Uberlândia, Minas Gerais 38400-902, Brazil
| | - Rogério J Baierle
- Departamento de Física, Universidade Federal de Santa Maria, Santa Maria, Rio Grande do Sul 97105-990, Brazil
| | - Roberto H Miwa
- Instituto de Física, Universidade Federal de Uberlândia, Uberlândia, Minas Gerais 38400-902, Brazil
| | - Tome M Schmidt
- Instituto de Física, Universidade Federal de Uberlândia, Uberlândia, Minas Gerais 38400-902, Brazil
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37
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Li JY, Kang XY, Zhang Y, Li S, Yao Y. Two-dimensional quadratic Weyl points, nodal loops, and spin-orbit Dirac points in PtS, PtSe, and PtTe monolayers. Phys Chem Chem Phys 2024; 26:4159-4165. [PMID: 38230417 DOI: 10.1039/d3cp05680e] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/18/2024]
Abstract
Topological quasiparticles have garnered significant research attention in condensed matter physics. However, they are exceedingly rare in two-dimensional systems, particularly those hosting unconventional topological quasiparticles. In this work, employing first-principles calculations and symmetry analysis, we demonstrate that PtS, PtSe, and PtTe monolayers serve as high-quality two-dimensional topological semimetal materials. These materials exhibit multiple types of topological quasiparticles around the Fermi level in the absence of spin-orbit coupling, such as conventional linear Weyl points and unconventional quadratic Weyl points in the PtS monolayer, as well as nodal loops in PtSe and PtTe monolayers. When spin-orbit coupling (SOC) is introduced, a tiny gap opens, transforming the systems into quantum spin hall insulators. Simultaneously, three spin-orbit Dirac points, robust against SOC, appear at the X, Y, and M points. We illustrate the symmetry protection, low-energy effective model, and edge states of these topological states. Our work provides an excellent material platform for studying novel two-dimensional topological quasiparticles and topological insulators.
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Affiliation(s)
- Jin-Yang Li
- School of Physics, Northwest University, Xi'an 710127, China.
- Shaanxi Key Laboratory for Theoretical Physics Frontiers, Xi'an 710127, China
| | - Xin-Yue Kang
- School of Physics, Northwest University, Xi'an 710127, China.
- Shaanxi Key Laboratory for Theoretical Physics Frontiers, Xi'an 710127, China
| | - Ying Zhang
- Department of Physics, Beijing Normal University, Beijing 100875, China
| | - Si Li
- School of Physics, Northwest University, Xi'an 710127, China.
- Shaanxi Key Laboratory for Theoretical Physics Frontiers, Xi'an 710127, China
| | - Yugui Yao
- Key Lab of Advanced Optoelectronic Quantum Architecture and Measurement (MOE), Beijing Key Lab of Nanophotonics & Ultrafine Optoelectronic Systems, and School of Physics, Beijing Institute of Technology, Beijing 100081, China
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38
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Marshall M, Wang H, Dos Santos AM, Haberl B, Xie W. Incommensurate Spiral Spin Order in CaMn 2Bi 2 Observed via High-Pressure Neutron Diffraction. Inorg Chem 2024; 63:1736-1744. [PMID: 38013417 DOI: 10.1021/acs.inorgchem.3c02379] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2023]
Abstract
High-pressure neutron diffraction is employed to investigate the magnetic behavior of CaMn2Bi2 in extreme conditions. In contrast to antiferromagnetic ordering on Mn atoms reported at ambient pressure, our results reveal that at high pressure, incommensurate spiral spin order emerges due to the interplay between magnetism on the Mn atoms and strong spin-orbit coupling on the Bi atoms: sinusoidal spin order is observed at pressures as high as 7.4 GPa. First-principles calculations with a noncollinear spin orientation demonstrate band crossing behavior near the Fermi level as a result of strong hybridization between the d orbitals of Mn and the p orbitals of Bi atoms. Competing antiferromagnetic order is observed at different temperatures in the partially frustrated lattice. Theoretical models have been developed to investigate spin dynamics. This research provides a unique toolbox for conducting experimental and theoretical magnetic and spin dynamics studies of magnetic quantum materials via high-pressure neutron diffraction.
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Affiliation(s)
- Madalynn Marshall
- Neutron Scattering Division, Neutron Sciences Directorate, Oak Ridge National Laboratory, Oak Ridge, Tennessee 37831, United States
| | - Haozhe Wang
- Department of Chemistry, Michigan State University, East Lansing, Michigan 48824, United States
| | - Antonio M Dos Santos
- Neutron Scattering Division, Neutron Sciences Directorate, Oak Ridge National Laboratory, Oak Ridge, Tennessee 37831, United States
| | - Bianca Haberl
- Neutron Scattering Division, Neutron Sciences Directorate, Oak Ridge National Laboratory, Oak Ridge, Tennessee 37831, United States
| | - Weiwei Xie
- Department of Chemistry, Michigan State University, East Lansing, Michigan 48824, United States
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Zheng Z, Zeng T, Zhao T, Shi S, Ren L, Zhang T, Jia L, Gu Y, Xiao R, Zhou H, Zhang Q, Lu J, Wang G, Zhao C, Li H, Tay BK, Chen J. Effective electrical manipulation of a topological antiferromagnet by orbital torques. Nat Commun 2024; 15:745. [PMID: 38272914 PMCID: PMC10811228 DOI: 10.1038/s41467-024-45109-1] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/25/2023] [Accepted: 01/09/2024] [Indexed: 01/27/2024] Open
Abstract
The electrical control of the non-trivial topology in Weyl antiferromagnets is of great interest for the development of next-generation spintronic devices. Recent studies suggest that the spin Hall effect can switch the topological antiferromagnetic order. However, the switching efficiency remains relatively low. Here, we demonstrate the effective manipulation of antiferromagnetic order in the Weyl semimetal Mn3Sn using orbital torques originating from either metal Mn or oxide CuOx. Although Mn3Sn can convert orbital current to spin current on its own, we find that inserting a heavy metal layer, such as Pt, of appropriate thickness can effectively reduce the critical switching current density by one order of magnitude. In addition, we show that the memristor-like switching behaviour of Mn3Sn can mimic the potentiation and depression processes of a synapse with high linearity-which may be beneficial for constructing accurate artificial neural networks. Our work paves a way for manipulating the topological antiferromagnetic order and may inspire more high-performance antiferromagnetic functional devices.
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Affiliation(s)
- Zhenyi Zheng
- Department of Materials Science and Engineering, National University of Singapore, Singapore, 117575, Singapore
| | - Tao Zeng
- Department of Materials Science and Engineering, National University of Singapore, Singapore, 117575, Singapore
| | - Tieyang Zhao
- Department of Materials Science and Engineering, National University of Singapore, Singapore, 117575, Singapore
| | - Shu Shi
- Department of Materials Science and Engineering, National University of Singapore, Singapore, 117575, Singapore
| | - Lizhu Ren
- Department of Electrical and Computer Engineering, National University of Singapore, Singapore, 117575, Singapore
| | - Tongtong Zhang
- Centre for Micro- and Nano-Electronics (CMNE), School of Electrical and Electronic Engineering, Nanyang Technological University, 639798, Singapore, Singapore
| | - Lanxin Jia
- Department of Materials Science and Engineering, National University of Singapore, Singapore, 117575, Singapore
| | - Youdi Gu
- Department of Materials Science and Engineering, National University of Singapore, Singapore, 117575, Singapore
| | - Rui Xiao
- Department of Materials Science and Engineering, National University of Singapore, Singapore, 117575, Singapore
| | - Hengan Zhou
- Department of Materials Science and Engineering, National University of Singapore, Singapore, 117575, Singapore
| | - Qihan Zhang
- Department of Materials Science and Engineering, National University of Singapore, Singapore, 117575, Singapore
| | - Jiaqi Lu
- Department of Materials Science and Engineering, National University of Singapore, Singapore, 117575, Singapore
| | - Guilei Wang
- Beijing Superstring Academy of Memory Technology, Beijing, 100176, China
| | - Chao Zhao
- Beijing Superstring Academy of Memory Technology, Beijing, 100176, China
| | - Huihui Li
- Beijing Superstring Academy of Memory Technology, Beijing, 100176, China.
| | - Beng Kang Tay
- Centre for Micro- and Nano-Electronics (CMNE), School of Electrical and Electronic Engineering, Nanyang Technological University, 639798, Singapore, Singapore.
| | - Jingsheng Chen
- Department of Materials Science and Engineering, National University of Singapore, Singapore, 117575, Singapore.
- Chongqing Research Institute, National University of Singapore, Chongqing, 401120, China.
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40
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Li Z, Pan B, Zhou P, Kang R, He S, Peng X, Sun L. Symmetry-enforced fourfold degenerate phonons in noncentrosymmetric space groups. JOURNAL OF PHYSICS. CONDENSED MATTER : AN INSTITUTE OF PHYSICS JOURNAL 2024; 36:165701. [PMID: 38190732 DOI: 10.1088/1361-648x/ad1bf7] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 08/27/2023] [Accepted: 01/08/2024] [Indexed: 01/10/2024]
Abstract
Multifold degenerate phonons have received much attention due to their nontrivial monopole topological charge and fascinating boundary states. Although Yuet alrecently provides a comprehensive list of all potential nodal points for systems with specific space groups (SGs) (2022Sci. Bull.67375). However, our understanding of the fundamental mechanisms that give rise to the formation of fourfold-degenerate (FD) phonons is still limited. In this paper, we have directed our research towards investigating the generation mechanism of these FD phonons in noncentrosymmetric SGs. Using symmetry arguments andk⋅pmodel analysis, we have classified them into two categories: the first origins from the commutation/anticommutation relation of the little cogroup operations, and the second associates to the combination of threefold rotation, mirror and time-reversal symmetries. Moreover, the band dispersions of the FD phonons in the first group are required to be linear, whereas the band dispersions of the FD phonons in the second category may be quadratic. On the basis of first-principles calculations, we propose that K2Mg2O3and Na4SnSe4are representative candidates for the two categories, respectively. Furthermore, for each SG with fourfold degenerate phonons, we propose corresponding materials that must host the FD points. Our work not only deepens our understanding of the mechanisms underlying the formation of these FD phonons, but it also proposes practical materials for observing FD phonons in crystalline systems without inversion symmetry.
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Affiliation(s)
- Zehou Li
- Hunan Provincial Key laboratory of Thin Film Materials and Devices, School of Material Sciences and Engineering, Xiangtan University, Xiangtan 411105, People's Republic of China
- Hunan Key Laboratory for Micro-Nano Energy Materials and Devices, School of Physics and Optoelectronics, Xiangtan University, Hunan 411105, People's Republic of China
| | - Baoru Pan
- Hunan Provincial Key laboratory of Thin Film Materials and Devices, School of Material Sciences and Engineering, Xiangtan University, Xiangtan 411105, People's Republic of China
- Hunan Key Laboratory for Micro-Nano Energy Materials and Devices, School of Physics and Optoelectronics, Xiangtan University, Hunan 411105, People's Republic of China
| | - Pan Zhou
- Hunan Provincial Key laboratory of Thin Film Materials and Devices, School of Material Sciences and Engineering, Xiangtan University, Xiangtan 411105, People's Republic of China
| | - Ruirong Kang
- Hunan Provincial Key laboratory of Thin Film Materials and Devices, School of Material Sciences and Engineering, Xiangtan University, Xiangtan 411105, People's Republic of China
| | - Shenda He
- Hunan Provincial Key laboratory of Thin Film Materials and Devices, School of Material Sciences and Engineering, Xiangtan University, Xiangtan 411105, People's Republic of China
| | - Xiangyang Peng
- Hunan Key Laboratory for Micro-Nano Energy Materials and Devices, School of Physics and Optoelectronics, Xiangtan University, Hunan 411105, People's Republic of China
| | - Lizhong Sun
- Hunan Provincial Key laboratory of Thin Film Materials and Devices, School of Material Sciences and Engineering, Xiangtan University, Xiangtan 411105, People's Republic of China
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41
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Chen P, Wang J, Wang G, Ye B, Zhou L, Wang L, Wang J, Zhang W, Chen W, Mei J, He H. Asymmetric edge supercurrents in MoTe 2 Josephson junctions. NANOSCALE ADVANCES 2024; 6:690-696. [PMID: 38235086 PMCID: PMC10791112 DOI: 10.1039/d3na00884c] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 10/14/2023] [Accepted: 12/13/2023] [Indexed: 01/19/2024]
Abstract
To investigate the higher order topology in MoTe2, the supercurrent interference phenomena in Nb/MoTe2/Nb planar Josephson junctions have been systematically studied. By analyzing the obtained interference pattern of the critical supercurrents and performing a comparative study of the edge-touched and untouched junctions, it's found that the supercurrent is dominated by the edges, rather than the bulk or surfaces of MoTe2. An asymmetric Josephson effect with a field-tunable sign is also observed, indicating the nontrivial origin of the edge states. These results not only provide initial evidence for the hinge states in the higher order topological insulator MoTe2, but also demonstrate the potential applications of MoTe2-based Josephson junctions in rectifying the supercurrent.
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Affiliation(s)
- Pingbo Chen
- Department of Physics, Harbin Institute of Technology Harbin 150001 China
- Department of Physics, Southern University of Science and Technology Shenzhen 518055 China
| | - Jinhua Wang
- Department of Physics, Southern University of Science and Technology Shenzhen 518055 China
| | - Gongqi Wang
- Department of Physics, Southern University of Science and Technology Shenzhen 518055 China
| | - Bicong Ye
- Department of Physics, Southern University of Science and Technology Shenzhen 518055 China
- Department of Physics, The Hong Kong University of Science and Technology Clear Water Bay Hong Kong 999077 China
| | - Liang Zhou
- Department of Physics, Southern University of Science and Technology Shenzhen 518055 China
| | - Le Wang
- Shenzhen Institute for Quantum Science and Engineering, Southern University of Science and Technology Shenzhen 518055 China
| | - Jiannong Wang
- Department of Physics, The Hong Kong University of Science and Technology Clear Water Bay Hong Kong 999077 China
| | - Wenqing Zhang
- Department of Materials Science and Engineering, Southern University of Science and Technology Shenzhen 518055 China
- Shenzhen Key Laboratory for Advanced Quantum Functional Materials and Devices, Southern University of Science and Technology Shenzhen 518055 China
| | - Weiqiang Chen
- Department of Physics, Southern University of Science and Technology Shenzhen 518055 China
- Shenzhen Key Laboratory for Advanced Quantum Functional Materials and Devices, Southern University of Science and Technology Shenzhen 518055 China
| | - Jiawei Mei
- Department of Physics, Southern University of Science and Technology Shenzhen 518055 China
- Shenzhen Key Laboratory for Advanced Quantum Functional Materials and Devices, Southern University of Science and Technology Shenzhen 518055 China
| | - Hongtao He
- Department of Physics, Southern University of Science and Technology Shenzhen 518055 China
- Shenzhen Key Laboratory for Advanced Quantum Functional Materials and Devices, Southern University of Science and Technology Shenzhen 518055 China
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42
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You JY, Su G, Feng YP. A versatile model with three-dimensional triangular lattice for unconventional transport and various topological effects. Natl Sci Rev 2024; 11:nwad114. [PMID: 38116092 PMCID: PMC10727845 DOI: 10.1093/nsr/nwad114] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/12/2022] [Revised: 02/18/2023] [Accepted: 03/02/2023] [Indexed: 12/21/2023] Open
Abstract
The finite Berry curvature in topological materials can induce many subtle phenomena, such as the anomalous Hall effect (AHE), spin Hall effect (SHE), anomalous Nernst effect (ANE), non-linear Hall effect (NLHE) and bulk photovoltaic effects. To explore these novel physics as well as their connection and coupling, a precise and effective model should be developed. Here, we propose such a versatile model-a 3D triangular lattice with alternating hopping parameters, which can yield various topological phases, including kagome bands, triply degenerate fermions, double Weyl semimetals and so on. We reveal that this special lattice can present unconventional transport due to its unique topological surface states and the aforementioned topological phenomena, such as AHE, ANE, NLHE and the topological photocurrent effect. In addition, we also provide a number of material candidates that have been synthesized experimentally with this lattice, and discuss two materials, including a non-magnetic triangular system for SHE, NLHE and the shift current, and a ferromagnetic triangular lattice for AHE and ANE. Our work provides an excellent platform, including both the model and materials, for the study of Berry-curvature-related physics.
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Affiliation(s)
- Jing-Yang You
- Department of Physics, National University of Singapore, Singapore 117551, Singapore
| | - Gang Su
- Kavli Institute for Theoretical Sciences, and CAS Center for Excellence in Topological Quantum Computation, University of Chinese Academy of Sciences, Beijing 100190, China
| | - Yuan Ping Feng
- Department of Physics, National University of Singapore, Singapore 117551, Singapore
- Centre for Advanced 2D Materials, National University of Singapore, Singapore 117546, Singapore
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43
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Wang X, Yi C, Felser C. Chiral Quantum Materials: When Chemistry Meets Physics. ADVANCED MATERIALS (DEERFIELD BEACH, FLA.) 2023:e2308746. [PMID: 38126622 DOI: 10.1002/adma.202308746] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 08/28/2023] [Revised: 12/01/2023] [Indexed: 12/23/2023]
Abstract
Chirality is a fundamental property of nature with relevance in biochemistry and physics, particularly in the field of catalysis. Understanding the mechanisms underlying chirality transfer is crucial for advancing the knowledge of chiral-related catalysis. Chiral quantum materials with intriguing chirality-dependent electronic properties, such as spin-orbital coupling (SOC) and exotic spin/orbital angular momentum (SAM/OAM), open novel avenues for linking solid-state topologies with chiral catalysis. In this review, the growth of topological homochiral crystals (THCs) is described, and their applications in heterogeneous catalysis, including hydrogen evolution reaction (HER), oxygen electrocatalysis, and asymmetric catalysis are summarized. A possible link between chirality-dependent electronic properties and heterogeneous catalysis is discussed. Finally, existing challenges in this field are highlighted, and a brief outlook on the impact of THCs on the overarching chemical-physical research is presented.
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Affiliation(s)
- Xia Wang
- Max Planck Institute for Chemical Physics of Solids, 01187, Dresden, Germany
| | - Changjiang Yi
- Max Planck Institute for Chemical Physics of Solids, 01187, Dresden, Germany
| | - Claudia Felser
- Max Planck Institute for Chemical Physics of Solids, 01187, Dresden, Germany
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44
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Zivieri R, Lumetti S, Létang J. High-Mobility Topological Semimetals as Novel Materials for Huge Magnetoresistance Effect and New Type of Quantum Hall Effect. MATERIALS (BASEL, SWITZERLAND) 2023; 16:7579. [PMID: 38138720 PMCID: PMC10744697 DOI: 10.3390/ma16247579] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 11/09/2023] [Revised: 12/04/2023] [Accepted: 12/06/2023] [Indexed: 12/24/2023]
Abstract
The quantitative description of electrical and magnetotransport properties of solid-state materials has been a remarkable challenge in materials science over recent decades. Recently, the discovery of a novel class of materials-the topological semimetals-has led to a growing interest in the full understanding of their magnetotransport properties. In this review, the strong interplay among topology, band structure, and carrier mobility in recently discovered high carrier mobility topological semimetals is discussed and their effect on their magnetotransport properties is outlined. Their large magnetoresistance effect, especially in the Hall transverse configuration, and a new version of a three-dimensional quantum Hall effect observed in high-mobility Weyl and Dirac semimetals are reviewed. The possibility of designing novel quantum sensors and devices based on solid-state semimetals is also examined.
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Affiliation(s)
| | | | - Jérémy Létang
- Silicon Austria Labs, 9524 Villach, Austria; (S.L.); (J.L.)
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45
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Skaggs CM, Ryu DC, Bhandari H, Xin Y, Kang CJ, Lapidus SH, Siegfried PE, Ghimire NJ, Tan X. IrGe 4: A Predicted Weyl-Metal with a Chiral Crystal Structure. Inorg Chem 2023; 62:19395-19403. [PMID: 37983308 DOI: 10.1021/acs.inorgchem.3c01528] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2023]
Abstract
Polycrystalline IrGe4 was synthesized by annealing elements at 800 °C for 240 h, and the composition was confirmed by energy-dispersive X-ray spectroscopy. IrGe4 adopts a chiral crystal structure (space group P3121) instead of a polar crystal structure (P31), which was corroborated by the convergent-beam electron diffraction and Rietveld refinements using synchrotron powder X-ray diffraction data. The crystal structure features layers of IrGe8 polyhedra along the b axis, and the layers are connected by edge- and corner-sharing. Each layer consists of corner-shared [Ir3Ge20] trimers, which are formed by three IrGe8 polyhedra connected by edge-sharing. Temperature-dependent resistivity indicates metallic behavior. The magnetoresistance increases with increasing applied magnetic field, and the nonsaturating magnetoresistance reaches 11.5% at 9 T and 10 K. The Hall resistivity suggests that holes are the majority carrier type, with a carrier concentration of 4.02 × 1021 cm-3 at 300 K. Electronic band structures calculated by density functional theory reveal a Weyl point with a chiral charge of +3 above the Fermi level.
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Affiliation(s)
- Callista M Skaggs
- Department of Chemistry and Biochemistry, George Mason University, Fairfax, Virginia 22030, United States
| | - Dong-Choon Ryu
- Department of Physics, Chungnam National University, Daejeon 34134, Republic of Korea
- Institute of Quantum Systems, Chungnam National University, Daejeon 34134, Republic of Korea
| | - Hari Bhandari
- Department of Physics and Astronomy, George Mason University, Fairfax, Virginia 22030, United States
- Quantum Science and Engineering Center, George Mason University, Fairfax, Virginia 22030, United States
| | - Yan Xin
- National High Magnetic Field Laboratory, Florida State University, Tallahassee, Florida 32310, United States
| | - Chang-Jong Kang
- Department of Physics, Chungnam National University, Daejeon 34134, Republic of Korea
- Institute of Quantum Systems, Chungnam National University, Daejeon 34134, Republic of Korea
| | - Saul H Lapidus
- Advanced Photon Source, Argonne National Laboratory, Argonne, Illinois 60439, United States
| | - Peter E Siegfried
- Department of Physics and Astronomy, George Mason University, Fairfax, Virginia 22030, United States
- Quantum Science and Engineering Center, George Mason University, Fairfax, Virginia 22030, United States
| | - Nirmal J Ghimire
- Department of Physics and Astronomy and Stavropoulos Center for Complex Quantum Matter, University of Notre Dame, Notre Dame, Indiana 46556, United States
| | - Xiaoyan Tan
- Department of Chemistry and Biochemistry, George Mason University, Fairfax, Virginia 22030, United States
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46
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Wang R, Zhang J, Li T, Chen K, Li Z, Wu M, Ling L, Xi C, Hong K, Miao L, Yuan S, Chen T, Wang J. SdH Oscillations from the Dirac Surface State in the Fermi-Arc Antiferromagnet NdBi. ADVANCED SCIENCE (WEINHEIM, BADEN-WURTTEMBERG, GERMANY) 2023; 10:e2303978. [PMID: 37877606 PMCID: PMC10724392 DOI: 10.1002/advs.202303978] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 06/21/2023] [Revised: 08/31/2023] [Indexed: 10/26/2023]
Abstract
The recent progress in CuMnAs and Mn3X (X = Sn, Ge, Pt) shows that antiferromagnets (AFMs) provide a promising platform for advanced spintronics device innovations. Most recently, a switchable Fermi-arc is discovered by the ARPES technique in antiferromagnet NdBi, but the knowledge about electron-transport property and the manipulability of the magnetic structure in NdBi is still vacant to date. In this study, SdH oscillations are successfully verified from the Dirac surface states (SSs) with 2-dimensionality and nonzero Berry phase. Particularly, it is observed that the spin-flop transition only appears when the external magnetical field is applied along [001] direction, and features obvious hysteresis for the first time in NdBi, which provides a powerful handle for adjusting the spin texture in NdBi. Crucially, the DFT shows the Dirac cone and the Fermi arc strongly depend on the high-order magnetic structure of NdBi and further reveals the orbital magnetic moment of Nd plays a crucial role in fostering the peculiar SSs, leading to unveil the mystery of the band-splitting effect and to manipulate the electronic transport, high-effectively, in the thin film works in NdBi. It is believed that this study provides important guidance for the development of new antiferromagnet-based spintronics devices based on cutting-edge rare-earth monopnictides.
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Affiliation(s)
- Ruoqi Wang
- Key Laboratory of Quantum Materials and Devices of Ministry of EducationSchool of PhysicsSoutheast UniversityNanjing211189China
| | - Junchao Zhang
- Key Laboratory of Quantum Materials and Devices of Ministry of EducationSchool of PhysicsSoutheast UniversityNanjing211189China
| | - Tian Li
- High Magnetic Field LaboratoryChinese Academy of SciencesHefei230031China
| | - Keming Chen
- Key Laboratory of Quantum Materials and Devices of Ministry of EducationSchool of PhysicsSoutheast UniversityNanjing211189China
| | - Zhengyu Li
- High Magnetic Field LaboratoryChinese Academy of SciencesHefei230031China
| | - Mingliang Wu
- Key Laboratory of Quantum Materials and Devices of Ministry of EducationSchool of PhysicsSoutheast UniversityNanjing211189China
| | - Langsheng Ling
- High Magnetic Field LaboratoryChinese Academy of SciencesHefei230031China
| | - Chuanying Xi
- High Magnetic Field LaboratoryChinese Academy of SciencesHefei230031China
| | - Kunquan Hong
- Key Laboratory of Quantum Materials and Devices of Ministry of EducationSchool of PhysicsSoutheast UniversityNanjing211189China
| | - Lin Miao
- Key Laboratory of Quantum Materials and Devices of Ministry of EducationSchool of PhysicsSoutheast UniversityNanjing211189China
| | - Shijun Yuan
- Key Laboratory of Quantum Materials and Devices of Ministry of EducationSchool of PhysicsSoutheast UniversityNanjing211189China
| | - Taishi Chen
- Key Laboratory of Quantum Materials and Devices of Ministry of EducationSchool of PhysicsSoutheast UniversityNanjing211189China
| | - Jinlan Wang
- Key Laboratory of Quantum Materials and Devices of Ministry of EducationSchool of PhysicsSoutheast UniversityNanjing211189China
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47
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Li C, Zhang J, Wang Y, Liu H, Guo Q, Rienks E, Chen W, Bertran F, Yang H, Phuyal D, Fedderwitz H, Thiagarajan B, Dendzik M, Berntsen MH, Shi Y, Xiang T, Tjernberg O. Emergence of Weyl fermions by ferrimagnetism in a noncentrosymmetric magnetic Weyl semimetal. Nat Commun 2023; 14:7185. [PMID: 37938548 PMCID: PMC10632385 DOI: 10.1038/s41467-023-42996-8] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/19/2023] [Accepted: 10/26/2023] [Indexed: 11/09/2023] Open
Abstract
Condensed matter physics has often provided a platform for investigating the interplay between particles and fields in cases that have not been observed in high-energy physics. Here, using angle-resolved photoemission spectroscopy, we provide an example of this by visualizing the electronic structure of a noncentrosymmetric magnetic Weyl semimetal candidate NdAlSi in both the paramagnetic and ferrimagnetic states. We observe surface Fermi arcs and bulk Weyl fermion dispersion as well as the emergence of new Weyl fermions in the ferrimagnetic state. Our results establish NdAlSi as a magnetic Weyl semimetal and provide an experimental observation of ferrimagnetic regulation of Weyl fermions in condensed matter.
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Affiliation(s)
- Cong Li
- Department of Applied Physics, KTH Royal Institute of Technology, Stockholm, 11419, Sweden.
- Department of Applied Physics, Stanford University, Stanford, CA, 94305, USA.
| | - Jianfeng Zhang
- Beijing National Laboratory for Condensed Matter Physics, Institute of Physics, Chinese Academy of Sciences, Beijing, 100190, China
| | - Yang Wang
- Department of Applied Physics, KTH Royal Institute of Technology, Stockholm, 11419, Sweden
| | - Hongxiong Liu
- Beijing National Laboratory for Condensed Matter Physics, Institute of Physics, Chinese Academy of Sciences, Beijing, 100190, China
| | - Qinda Guo
- Department of Applied Physics, KTH Royal Institute of Technology, Stockholm, 11419, Sweden
| | - Emile Rienks
- Helmholtz-Zentrum Berlin für Materialien und Energie, Elektronenspeicherring BESSY II, Albert-Einstein-Straße 15, 12489, Berlin, Germany
| | - Wanyu Chen
- Department of Applied Physics, KTH Royal Institute of Technology, Stockholm, 11419, Sweden
| | - Francois Bertran
- Synchrotron SOLEIL, L'Orme des Merisiers, Départementale 128, 91190, Saint-Aubin, France
| | - Huancheng Yang
- Department of Physics and Beijing Key Laboratory of Opto-electronic Functional Materials & Micro-nano Devices, Renmin University of China, Beijing, 100872, China
| | - Dibya Phuyal
- Department of Applied Physics, KTH Royal Institute of Technology, Stockholm, 11419, Sweden
| | | | | | - Maciej Dendzik
- Department of Applied Physics, KTH Royal Institute of Technology, Stockholm, 11419, Sweden
| | - Magnus H Berntsen
- Department of Applied Physics, KTH Royal Institute of Technology, Stockholm, 11419, Sweden
| | - Youguo Shi
- Beijing National Laboratory for Condensed Matter Physics, Institute of Physics, Chinese Academy of Sciences, Beijing, 100190, China
| | - Tao Xiang
- Beijing National Laboratory for Condensed Matter Physics, Institute of Physics, Chinese Academy of Sciences, Beijing, 100190, China
| | - Oscar Tjernberg
- Department of Applied Physics, KTH Royal Institute of Technology, Stockholm, 11419, Sweden.
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48
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Faraei Z, Jafari SA. Synthetic complex Weyl superconductors, chiral Josephson effect and synthetic half-vortices. Sci Rep 2023; 13:17976. [PMID: 37864055 PMCID: PMC10589258 DOI: 10.1038/s41598-023-44910-0] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/22/2022] [Accepted: 10/13/2023] [Indexed: 10/22/2023] Open
Abstract
We show that the most generic form of spin-singlet superconducting order parameter for chiral fermions in systems with broken time reversal symmetry and inversion symmetry is of the [Formula: see text] where [Formula: see text] is the usual order parameter and [Formula: see text] is the pseudo-scalar order parameter. After factoring out the U(1) phase [Formula: see text], this form of superconductivity admits yet additional complex structure in the plane of [Formula: see text]. The polar angle [Formula: see text] in this plane, which we call the chiral angle, can be controlled by the external flux bias. We present a synthetic setup based on stacking of topological insulators (TIs) and superconductors (SCs). Alternatively flux biasing the superconductors with a fluxes [Formula: see text] leads to [Formula: see text], where [Formula: see text] is the superconducting order parameter of the SC layers, and the chiral angle [Formula: see text] is directly given by the flux [Formula: see text] in units of the flux quantum [Formula: see text]. This can be used as a building block to construct a two-dimensional Josephson array. In this setup [Formula: see text] will be a background field defining a pseudoscalar [Formula: see text] that can be tuned to desired configuration. While in a uniform background field [Formula: see text] the dynamics of [Formula: see text] is given by standard XY model and its associated vortices, a staggered background [Formula: see text] (or equivalently [Formula: see text] and [Formula: see text] in alternating lattice sites) creates a new set of minima for the [Formula: see text] field that will support half-vortex excitations. An isolated single engineered "half-vortex" in the [Formula: see text] field in an otherwise uniform background will bind a [Formula: see text]-half-vortex. This is similar to the way a p-wave superconducting vortex core binds a Majorana fermion.
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Affiliation(s)
- Zahra Faraei
- Department of Physics, Institute for Advanced Studies in Basic Sciences (IASBS), Zanjan, 45137-66731, Iran.
| | - Seyed Akbar Jafari
- Sharif University of Technology, Department of Physics, Tehran, 11155-9161, Iran
- Institute for Advanced Simulations, Forschungszentrum Jülich, 52425, Jülich, Germany
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49
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Pan Y, Cui C, Chen Q, Chen F, Zhang L, Ren Y, Han N, Li W, Li X, Yu ZM, Chen H, Yang Y. Real higher-order Weyl photonic crystal. Nat Commun 2023; 14:6636. [PMID: 37857622 PMCID: PMC10587095 DOI: 10.1038/s41467-023-42457-2] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/06/2023] [Accepted: 10/11/2023] [Indexed: 10/21/2023] Open
Abstract
Higher-order Weyl semimetals are a family of recently predicted topological phases simultaneously showcasing unconventional properties derived from Weyl points, such as chiral anomaly, and multidimensional topological phenomena originating from higher-order topology. The higher-order Weyl semimetal phases, with their higher-order topology arising from quantized dipole or quadrupole bulk polarizations, have been demonstrated in phononics and circuits. Here, we experimentally discover a class of higher-order Weyl semimetal phase in a three-dimensional photonic crystal (PhC), exhibiting the concurrence of the surface and hinge Fermi arcs from the nonzero Chern number and the nontrivial generalized real Chern number, respectively, coined a real higher-order Weyl PhC. Notably, the projected two-dimensional subsystem with kz = 0 is a real Chern insulator, belonging to the Stiefel-Whitney class with real Bloch wavefunctions, which is distinguished fundamentally from the Chern class with complex Bloch wavefunctions. Our work offers an ideal photonic platform for exploring potential applications and material properties associated with the higher-order Weyl points and the Stiefel-Whitney class of topological phases.
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Affiliation(s)
- Yuang Pan
- Interdisciplinary Center for Quantum Information, State Key Laboratory of Extreme Photonics and Instrumentation, ZJU-Hangzhou Global Scientific and Technological Innovation Center, Zhejiang University, Hangzhou, 310027, China
- International Joint Innovation Center, The Electromagnetics Academy at Zhejiang University, Zhejiang University, Haining, 314400, China
- Key Lab. of Advanced Micro/Nano Electronic Devices & Smart Systems of Zhejiang, Jinhua Institute of Zhejiang University, Zhejiang University, Jinhua, 321099, China
- Shaoxing Institute of Zhejiang University, Zhejiang University, Shaoxing, 312000, China
| | - Chaoxi Cui
- Centre for Quantum Physics, Key Laboratory of Advanced Optoelectronic Quantum Architecture and Measurement (MOE), School of Physics, Beijing Institute of Technology, Beijing, 100081, China
- Beijing Key Laboratory of Nanophotonics and Ultrafine Optoelectronic Systems, School of Physics, Beijing Institute of Technology, Beijing, 100081, China
| | - Qiaolu Chen
- Interdisciplinary Center for Quantum Information, State Key Laboratory of Extreme Photonics and Instrumentation, ZJU-Hangzhou Global Scientific and Technological Innovation Center, Zhejiang University, Hangzhou, 310027, China
- International Joint Innovation Center, The Electromagnetics Academy at Zhejiang University, Zhejiang University, Haining, 314400, China
- Key Lab. of Advanced Micro/Nano Electronic Devices & Smart Systems of Zhejiang, Jinhua Institute of Zhejiang University, Zhejiang University, Jinhua, 321099, China
- Shaoxing Institute of Zhejiang University, Zhejiang University, Shaoxing, 312000, China
| | - Fujia Chen
- Interdisciplinary Center for Quantum Information, State Key Laboratory of Extreme Photonics and Instrumentation, ZJU-Hangzhou Global Scientific and Technological Innovation Center, Zhejiang University, Hangzhou, 310027, China
- International Joint Innovation Center, The Electromagnetics Academy at Zhejiang University, Zhejiang University, Haining, 314400, China
- Key Lab. of Advanced Micro/Nano Electronic Devices & Smart Systems of Zhejiang, Jinhua Institute of Zhejiang University, Zhejiang University, Jinhua, 321099, China
- Shaoxing Institute of Zhejiang University, Zhejiang University, Shaoxing, 312000, China
| | - Li Zhang
- Interdisciplinary Center for Quantum Information, State Key Laboratory of Extreme Photonics and Instrumentation, ZJU-Hangzhou Global Scientific and Technological Innovation Center, Zhejiang University, Hangzhou, 310027, China
- International Joint Innovation Center, The Electromagnetics Academy at Zhejiang University, Zhejiang University, Haining, 314400, China
- Key Lab. of Advanced Micro/Nano Electronic Devices & Smart Systems of Zhejiang, Jinhua Institute of Zhejiang University, Zhejiang University, Jinhua, 321099, China
- Shaoxing Institute of Zhejiang University, Zhejiang University, Shaoxing, 312000, China
| | - Yudong Ren
- Interdisciplinary Center for Quantum Information, State Key Laboratory of Extreme Photonics and Instrumentation, ZJU-Hangzhou Global Scientific and Technological Innovation Center, Zhejiang University, Hangzhou, 310027, China
- International Joint Innovation Center, The Electromagnetics Academy at Zhejiang University, Zhejiang University, Haining, 314400, China
- Key Lab. of Advanced Micro/Nano Electronic Devices & Smart Systems of Zhejiang, Jinhua Institute of Zhejiang University, Zhejiang University, Jinhua, 321099, China
- Shaoxing Institute of Zhejiang University, Zhejiang University, Shaoxing, 312000, China
| | - Ning Han
- Interdisciplinary Center for Quantum Information, State Key Laboratory of Extreme Photonics and Instrumentation, ZJU-Hangzhou Global Scientific and Technological Innovation Center, Zhejiang University, Hangzhou, 310027, China
- International Joint Innovation Center, The Electromagnetics Academy at Zhejiang University, Zhejiang University, Haining, 314400, China
- Key Lab. of Advanced Micro/Nano Electronic Devices & Smart Systems of Zhejiang, Jinhua Institute of Zhejiang University, Zhejiang University, Jinhua, 321099, China
- Shaoxing Institute of Zhejiang University, Zhejiang University, Shaoxing, 312000, China
| | - Wenhao Li
- Interdisciplinary Center for Quantum Information, State Key Laboratory of Extreme Photonics and Instrumentation, ZJU-Hangzhou Global Scientific and Technological Innovation Center, Zhejiang University, Hangzhou, 310027, China
- International Joint Innovation Center, The Electromagnetics Academy at Zhejiang University, Zhejiang University, Haining, 314400, China
- Key Lab. of Advanced Micro/Nano Electronic Devices & Smart Systems of Zhejiang, Jinhua Institute of Zhejiang University, Zhejiang University, Jinhua, 321099, China
- Shaoxing Institute of Zhejiang University, Zhejiang University, Shaoxing, 312000, China
| | - Xinrui Li
- Interdisciplinary Center for Quantum Information, State Key Laboratory of Extreme Photonics and Instrumentation, ZJU-Hangzhou Global Scientific and Technological Innovation Center, Zhejiang University, Hangzhou, 310027, China
- International Joint Innovation Center, The Electromagnetics Academy at Zhejiang University, Zhejiang University, Haining, 314400, China
- Key Lab. of Advanced Micro/Nano Electronic Devices & Smart Systems of Zhejiang, Jinhua Institute of Zhejiang University, Zhejiang University, Jinhua, 321099, China
- Shaoxing Institute of Zhejiang University, Zhejiang University, Shaoxing, 312000, China
| | - Zhi-Ming Yu
- Centre for Quantum Physics, Key Laboratory of Advanced Optoelectronic Quantum Architecture and Measurement (MOE), School of Physics, Beijing Institute of Technology, Beijing, 100081, China.
- Beijing Key Laboratory of Nanophotonics and Ultrafine Optoelectronic Systems, School of Physics, Beijing Institute of Technology, Beijing, 100081, China.
| | - Hongsheng Chen
- Interdisciplinary Center for Quantum Information, State Key Laboratory of Extreme Photonics and Instrumentation, ZJU-Hangzhou Global Scientific and Technological Innovation Center, Zhejiang University, Hangzhou, 310027, China.
- International Joint Innovation Center, The Electromagnetics Academy at Zhejiang University, Zhejiang University, Haining, 314400, China.
- Key Lab. of Advanced Micro/Nano Electronic Devices & Smart Systems of Zhejiang, Jinhua Institute of Zhejiang University, Zhejiang University, Jinhua, 321099, China.
- Shaoxing Institute of Zhejiang University, Zhejiang University, Shaoxing, 312000, China.
| | - Yihao Yang
- Interdisciplinary Center for Quantum Information, State Key Laboratory of Extreme Photonics and Instrumentation, ZJU-Hangzhou Global Scientific and Technological Innovation Center, Zhejiang University, Hangzhou, 310027, China.
- International Joint Innovation Center, The Electromagnetics Academy at Zhejiang University, Zhejiang University, Haining, 314400, China.
- Key Lab. of Advanced Micro/Nano Electronic Devices & Smart Systems of Zhejiang, Jinhua Institute of Zhejiang University, Zhejiang University, Jinhua, 321099, China.
- Shaoxing Institute of Zhejiang University, Zhejiang University, Shaoxing, 312000, China.
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50
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Singha R, Dalgaard KJ, Marchenko D, Krivenkov M, Rienks EDL, Jovanovic M, Teicher SML, Hu J, Salters TH, Lin J, Varykhalov A, Ong NP, Schoop LM. Colossal magnetoresistance in the multiple wave vector charge density wave regime of an antiferromagnetic Dirac semimetal. SCIENCE ADVANCES 2023; 9:eadh0145. [PMID: 37831777 PMCID: PMC10575584 DOI: 10.1126/sciadv.adh0145] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 02/04/2023] [Accepted: 09/11/2023] [Indexed: 10/15/2023]
Abstract
Colossal negative magnetoresistance is a well-known phenomenon, notably observed in hole-doped ferromagnetic manganites. It remains a major research topic due to its potential in technological applications. In contrast, topological semimetals show large but positive magnetoresistance, originated from the high-mobility charge carriers. Here, we show that in the highly electron-doped region, the Dirac semimetal CeSbTe demonstrates similar properties as the manganites. CeSb0.11Te1.90 hosts multiple charge density wave modulation vectors and has a complex magnetic phase diagram. We confirm that this compound is an antiferromagnetic Dirac semimetal. Despite having a metallic Fermi surface, the electronic transport properties are semiconductor-like and deviate from known theoretical models. An external magnetic field induces a semiconductor metal-like transition, which results in a colossal negative magnetoresistance. Moreover, signatures of the coupling between the charge density wave and a spin modulation are observed in resistivity. This spin modulation also produces a giant anomalous Hall response.
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Affiliation(s)
- Ratnadwip Singha
- Department of Chemistry, Princeton University, Princeton, NJ 08544, USA
| | | | - Dmitry Marchenko
- Helmholtz-Zentrum Berlin für Materialien und Energie, Elektronenspeicherring BESSY II, Albert-Einstein-Straße 15, 12489 Berlin, Germany
| | - Maxim Krivenkov
- Helmholtz-Zentrum Berlin für Materialien und Energie, Elektronenspeicherring BESSY II, Albert-Einstein-Straße 15, 12489 Berlin, Germany
| | - Emile D. L. Rienks
- Helmholtz-Zentrum Berlin für Materialien und Energie, Elektronenspeicherring BESSY II, Albert-Einstein-Straße 15, 12489 Berlin, Germany
| | - Milena Jovanovic
- Department of Chemistry, Princeton University, Princeton, NJ 08544, USA
| | - Samuel M. L. Teicher
- Materials Department and Materials Research Laboratory, University of California, Santa Barbara, Santa Barbara, CA. 93106, USA
| | - Jiayi Hu
- Department of Physics, Princeton University, Princeton, NJ 08544, USA
| | - Tyger H. Salters
- Department of Chemistry, Princeton University, Princeton, NJ 08544, USA
| | - Jingjing Lin
- Department of Physics, Princeton University, Princeton, NJ 08544, USA
| | - Andrei Varykhalov
- Helmholtz-Zentrum Berlin für Materialien und Energie, Elektronenspeicherring BESSY II, Albert-Einstein-Straße 15, 12489 Berlin, Germany
| | - N. Phuan Ong
- Department of Physics, Princeton University, Princeton, NJ 08544, USA
| | - Leslie M. Schoop
- Department of Chemistry, Princeton University, Princeton, NJ 08544, USA
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