151
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Berry curvature generation detected by Nernst responses in ferroelectric Weyl semimetal. Proc Natl Acad Sci U S A 2021; 118:2111855118. [PMID: 34706939 DOI: 10.1073/pnas.2111855118] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/27/2021] [Accepted: 09/21/2021] [Indexed: 11/18/2022] Open
Abstract
The quest for nonmagnetic Weyl semimetals with high tunability of phase has remained a demanding challenge. As the symmetry-breaking control parameter, the ferroelectric order can be steered to turn on/off the Weyl semimetals phase, adjust the band structures around the Fermi level, and enlarge/shrink the momentum separation of Weyl nodes which generate the Berry curvature as the emergent magnetic field. Here, we report the realization of a ferroelectric nonmagnetic Weyl semimetal based on indium-doped Pb1- x Sn x Te alloy in which the underlying inversion symmetry as well as mirror symmetry are broken with the strength of ferroelectricity adjustable via tuning the indium doping level and Sn/Pb ratio. The transverse thermoelectric effect (i.e., Nernst effect), both for out-of-plane and in-plane magnetic field geometry, is exploited as a Berry curvature-sensitive experimental probe to manifest the generation of Berry curvature via the redistribution of Weyl nodes under magnetic fields. The results demonstrate a clean, nonmagnetic Weyl semimetal coupled with highly tunable ferroelectric order, providing an ideal platform for manipulating the Weyl fermions in nonmagnetic systems.
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152
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Wu JF, Ke SS, Guo Y, Zhang HW, Lü HF. Noncentrosymmetric Weyl phase and topological phase transition in bulk MoTe. Phys Chem Chem Phys 2021; 23:23196-23202. [PMID: 34622258 DOI: 10.1039/d1cp02793j] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
Abstract
Ideal topological materials are those stable materials with less nontrivial band crossing near the Fermi surface and a long Fermi arc. By means of first-principles calculations, here we present that the 3D monochalcogenide molybdenum telluride (Pm-MoTe) without an inversion center shows a type-II Weyl semimetal (WSM) phase which cannot checked by symmetry index method. A total of eight Weyl points (WPs) are found in different quadrants of the Brillouin zone (BZ) of Pm-MoTe, which guarantee a long Fermi arc. The WSM phase is robust against the spin-orbit coupling (SOC) effect because of mirror symmetry and time reversal symmetry. It is also found that a topological phase transition can be tuned by strain. For different types of strain, the number of WPs can be effectively modulated to a minimum number, and their energies could be closer to Fermi level. These findings propose a promising material candidate that partly satisfies the ideal WSM criteria and extends the potential applications of the tunable topological phase.
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Affiliation(s)
- Jia-Fang Wu
- School of Physics and State Key Laboratory of Electronic Thin Films and Integrated Devices, University of Electronic Science and Technology of China, Chengdu 610054, China.
| | - Sha-Sha Ke
- School of Physics and State Key Laboratory of Electronic Thin Films and Integrated Devices, University of Electronic Science and Technology of China, Chengdu 610054, China.
| | - Yong Guo
- Department of Physics and State Key Laboratory of Low-Dimensional Quantum Physics, Tsinghua University, Beijing 100084, China
| | - Huai-Wu Zhang
- School of Physics and State Key Laboratory of Electronic Thin Films and Integrated Devices, University of Electronic Science and Technology of China, Chengdu 610054, China.
| | - Hai-Feng Lü
- School of Physics and State Key Laboratory of Electronic Thin Films and Integrated Devices, University of Electronic Science and Technology of China, Chengdu 610054, China. .,Department of Physics and State Key Laboratory of Low-Dimensional Quantum Physics, Tsinghua University, Beijing 100084, China
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153
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Kyrk TM, Scheifers JP, Thanabalasingam K, McCandless GT, Young DP, Chan JY. It Runs in the BaAl 4 Family: Relating the Structure and Properties of Middle Child Ln 2Co 3Ge 5 (Ln = Pr, Nd, and Sm) to its Siblings LnCo 2Ge 2 and LnCoGe 3. Inorg Chem 2021; 60:15343-15350. [PMID: 34609873 DOI: 10.1021/acs.inorgchem.1c01978] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Abstract
The BaAl4 prototype structure and its derivatives have been identified to host several topological quantum materials and noncentrosymmetric superconductors. Single crystals up to ∼3 mm × 3 mm × 5 mm of Ln2Co3Ge5 (Ln = Pr, Nd, and Sm) are obtained via flux growth utilizing Sn as metallic flux. The crystal structure is isostructural to the Lu2Co3Si5 structure type in the crystallographic space group C2/c. The temperature-dependent magnetization indicates magnetic ordering at 30 K for all three compounds. Pr2Co3Ge5 and Nd2Co3Ge5 exhibit complex magnetic behavior with spin reorientations before ordering antiferromagnetically around 6 K, whereas Sm2Co3Ge5 shows a clear antiferromagnetic behavior at 26 K. The structures and properties of Ln2Co3Ge5 (Ln = Pr, Nd, and Sm) are compared to those of the ThCr2Si2 and BaNiSn3 structure types. Herein, we present the optimized crystal growth, structure, and physical properties of Ln2Co3Ge5 (Ln = Pr, Nd, and Sm).
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Affiliation(s)
- Trent M Kyrk
- Department of Chemistry and Biochemistry, University of Texas at Dallas, Richardson, Texas 75080, United States
| | - Jan P Scheifers
- Department of Chemistry and Biochemistry, University of Texas at Dallas, Richardson, Texas 75080, United States
| | - Kulatheepan Thanabalasingam
- Department of Chemistry and Biochemistry, University of Texas at Dallas, Richardson, Texas 75080, United States
| | - Gregory T McCandless
- Department of Chemistry and Biochemistry, University of Texas at Dallas, Richardson, Texas 75080, United States
| | - David P Young
- Department of Physics and Astronomy, Louisiana State University, Baton Rouge, Louisiana 70803-4001, United States
| | - Julia Y Chan
- Department of Chemistry and Biochemistry, University of Texas at Dallas, Richardson, Texas 75080, United States
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154
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Elcoro L, Wieder BJ, Song Z, Xu Y, Bradlyn B, Bernevig BA. Magnetic topological quantum chemistry. Nat Commun 2021; 12:5965. [PMID: 34645841 PMCID: PMC8514474 DOI: 10.1038/s41467-021-26241-8] [Citation(s) in RCA: 24] [Impact Index Per Article: 8.0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/31/2021] [Accepted: 08/31/2021] [Indexed: 11/09/2022] Open
Abstract
For over 100 years, the group-theoretic characterization of crystalline solids has provided the foundational language for diverse problems in physics and chemistry. However, the group theory of crystals with commensurate magnetic order has remained incomplete for the past 70 years, due to the complicated symmetries of magnetic crystals. In this work, we complete the 100-year-old problem of crystalline group theory by deriving the small corepresentations, momentum stars, compatibility relations, and magnetic elementary band corepresentations of the 1,421 magnetic space groups (MSGs), which we have made freely accessible through tools on the Bilbao Crystallographic Server. We extend Topological Quantum Chemistry to the MSGs to form a complete, real-space theory of band topology in magnetic and nonmagnetic crystalline solids - Magnetic Topological Quantum Chemistry (MTQC). Using MTQC, we derive the complete set of symmetry-based indicators of electronic band topology, for which we identify symmetry-respecting bulk and anomalous surface and hinge states.
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Affiliation(s)
- Luis Elcoro
- Department of Condensed Matter Physics, University of the Basque Country UPV/EHU, Bilbao, Spain
| | - Benjamin J Wieder
- Department of Physics, Massachusetts Institute of Technology, Cambridge, MA, USA.
- Department of Physics, Northeastern University, Boston, MA, USA.
- Department of Physics, Princeton University, Princeton, NJ, USA.
| | - Zhida Song
- Department of Physics, Princeton University, Princeton, NJ, USA
| | - Yuanfeng Xu
- Max Planck Institute of Microstructure Physics, Halle, Germany
| | - Barry Bradlyn
- Department of Physics and Institute for Condensed Matter Theory, University of Illinois at Urbana-Champaign, Urbana, IL, USA
| | - B Andrei Bernevig
- Department of Physics, Princeton University, Princeton, NJ, USA.
- Donostia International Physics Center, Donostia-San Sebastian, Spain.
- IKERBASQUE, Basque Foundation for Science, Bilbao, Spain.
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155
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Rees D, Lu B, Sun Y, Manna K, Özgür R, Subedi S, Borrmann H, Felser C, Orenstein J, Torchinsky DH. Direct Measurement of Helicoid Surface States in RhSi Using Nonlinear Optics. PHYSICAL REVIEW LETTERS 2021; 127:157405. [PMID: 34678039 DOI: 10.1103/physrevlett.127.157405] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/09/2021] [Revised: 08/02/2021] [Accepted: 09/15/2021] [Indexed: 06/13/2023]
Abstract
Despite the fundamental nature of the edge state in topological physics, direct measurement of electronic and optical properties of the Fermi arcs of topological semimetals has posed a significant experimental challenge, as their response is often overwhelmed by the metallic bulk. However, laser-driven currents carried by surface and bulk states can propagate in different directions in nonsymmorphic crystals, allowing for the two components to be easily separated. Motivated by a recent theoretical prediction G. Chang et al., Phys. Rev. Lett. 124, 166404 (2020)PRLTAO0031-900710.1103/PhysRevLett.124.166404, we have measured the linear and circular photogalvanic effect currents deriving from the Fermi arcs of the nonsymmorphic, chiral Weyl semimetal RhSi over the 0.45-1.1 eV incident photon energy range. Our data are in good agreement with the predicted spectral shape of the circular photogalvanic effect as a function of photon energy, although the direction of the surface photocurrent departed from the theoretical expectation over the energy range studied. Surface currents arising from the linear photogalvanic effect were observed as well, with the unexpected result that only two of the six allowed tensor element were required to describe the measurements, suggesting an approximate emergent mirror symmetry inconsistent with the space group of the crystal.
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Affiliation(s)
- Dylan Rees
- Department of Physics, University of California, Berkeley, Berkeley, California 94720, USA
- Materials Science Division, Lawrence Berkeley National Laboratory, Berkeley, California 94720, USA
| | - Baozhu Lu
- Department of Physics, Temple University, Philadelphia, Pennsylvania 19122, USA
| | - Yue Sun
- Materials Science Division, Lawrence Berkeley National Laboratory, Berkeley, California 94720, USA
- Department of Chemistry, University of California, Berkeley, Berkeley, California 94720, USA
| | - Kaustuv Manna
- Max Planck Institute for Chemical Physics of Solids, Dresden D-01187, Germany
- Department of Physics, Indian Institute of Technology Delhi, New Delhi 110016, India
| | - Rüstem Özgür
- Department of Materials Science and Engineering, University of California, Berkeley, California 94720, USA
| | - Sujan Subedi
- Department of Physics, Temple University, Philadelphia, Pennsylvania 19122, USA
| | - Horst Borrmann
- Max Planck Institute for Chemical Physics of Solids, Dresden D-01187, Germany
| | - Claudia Felser
- Max Planck Institute for Chemical Physics of Solids, Dresden D-01187, Germany
| | - J Orenstein
- Department of Physics, University of California, Berkeley, Berkeley, California 94720, USA
- Materials Science Division, Lawrence Berkeley National Laboratory, Berkeley, California 94720, USA
| | - Darius H Torchinsky
- Department of Physics, Temple University, Philadelphia, Pennsylvania 19122, USA
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156
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Le C, Sun Y. Topology and symmetry of circular photogalvanic effect in the chiral multifold semimetals: a review. JOURNAL OF PHYSICS. CONDENSED MATTER : AN INSTITUTE OF PHYSICS JOURNAL 2021; 33:503003. [PMID: 34551401 DOI: 10.1088/1361-648x/ac2928] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/14/2021] [Accepted: 09/22/2021] [Indexed: 06/13/2023]
Abstract
The circular photogalvanic effect (CPGE) is the only possible quantized signal in chiral Weyl and multifold semimetals with inversion and mirror symmetries broken. Here, we review CPGE in the chiral multifold semimetals in terms of classification of CPGE tensor, the quantization of CPGE fromk⋅peffective model and topological semimetal RhSi family. Firstly, we give complete symmetric analysis of CPGE tensors for all nonmagnetic point groups, and get a table classifying matrix of response tensors. Secondly, the CPGE becomes a quantized response in the noncentrosymmetric topological semimetals, and depends on the Chern number of multifold fermions. Based onk⋅peffective model with linear dispersion, detailed derivations about the quantization of CPGE are given. Finally, according toab initioanalysis for the quantized CPGE based on noninteracting electronic structures, we review previous reports and make new calculations for the chiral topological semimetals in RhSi family, which can be separated into two groups. The first group, including RhSi, PtAl and CoSi, can be the promising candidates to exhibit a quantized CPGE trace, while the second group includes PdGa, PtGa and RhSn without a quantization.
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Affiliation(s)
- Congcong Le
- Max Planck Institute for Chemical Physics of Solids, 01187 Dresden, Germany
- RIKEN Interdisciplinary Theoretical and Mathematical Sciences (iTHEMS), Wako, Saitama 351-0198, Japan
| | - Yan Sun
- Max Planck Institute for Chemical Physics of Solids, 01187 Dresden, Germany
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157
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Qiu H, Xiao M, Zhang F, Qiu C. Higher-Order Dirac Sonic Crystals. PHYSICAL REVIEW LETTERS 2021; 127:146601. [PMID: 34652168 DOI: 10.1103/physrevlett.127.146601] [Citation(s) in RCA: 14] [Impact Index Per Article: 4.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 02/28/2021] [Accepted: 09/10/2021] [Indexed: 06/13/2023]
Abstract
Discovering new topological phases of matter is a major theme in fundamental physics and materials science. Dirac semimetal provides an exceptional platform for exploring topological phase transitions under symmetry breaking. Recent theoretical studies have revealed that a three-dimensional Dirac semimetal can harbor fascinating hinge states, a higher-order topological manifestation not known before. However, its realization in experiment is yet to be achieved. In this Letter, we propose a minimum model to construct a spinless higher-order Dirac semimetal protected by C_{6v} symmetry. By breaking different symmetries, this parent phase transitions into a variety of novel topological phases including higher-order topological insulator, higher-order Weyl semimetal, and higher-order nodal-ring semimetal. Furthermore, for the first time, we experimentally realize this unprecedented higher-order topological phase in a sonic crystal and present an unambiguous observation of the desired hinge states via momentum-space spectroscopy and real-space visualization. Our findings may offer new opportunities to manipulate classical waves such as sound and light.
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Affiliation(s)
- Huahui Qiu
- Key Laboratory of Artificial Micro- and Nano-Structures of Ministry of Education and School of Physics and Technology, Wuhan University, Wuhan 430072, China
| | - Meng Xiao
- Key Laboratory of Artificial Micro- and Nano-Structures of Ministry of Education and School of Physics and Technology, Wuhan University, Wuhan 430072, China
| | - Fan Zhang
- Department of Physics, University of Texas at Dallas, Richardson, Texas 75080, USA
| | - Chunyin Qiu
- Key Laboratory of Artificial Micro- and Nano-Structures of Ministry of Education and School of Physics and Technology, Wuhan University, Wuhan 430072, China
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158
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Singha R, Salters TH, Teicher SML, Lei S, Khoury JF, Ong NP, Schoop LM. Evolving Devil's Staircase Magnetization from Tunable Charge Density Waves in Nonsymmorphic Dirac Semimetals. ADVANCED MATERIALS (DEERFIELD BEACH, FLA.) 2021; 33:e2103476. [PMID: 34436807 DOI: 10.1002/adma.202103476] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/07/2021] [Revised: 06/18/2021] [Indexed: 06/13/2023]
Abstract
While several magnetic topological semimetals have been discovered in recent years, their band structures are far from ideal, often obscured by trivial bands at the Fermi energy. Square-net materials with clean, linearly dispersing bands show potential to circumvent this issue. CeSbTe, a square-net material, features multiple magnetic-field-controllable topological phases. Here, it is shown that in this material, even higher degrees of tunability can be achieved by changing the electron count at the square-net motif. Increased electron filling results in structural distortion and formation of charge density waves (CDWs). The modulation wave-vector evolves continuously leading to a region of multiple discrete CDWs and a corresponding complex "Devil's staircase" magnetic ground state. A series of fractionally quantized magnetization plateaus is observed, which implies direct coupling between CDW and a collective spin-excitation. It is further shown that the CDW creates a robust idealized nonsymmorphic Dirac semimetal, thus providing access to topological systems with rich magnetism.
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Affiliation(s)
- Ratnadwip Singha
- Department of Chemistry, Princeton University, Princeton, NJ, 08544, USA
| | - Tyger H Salters
- Department of Chemistry, Princeton University, Princeton, NJ, 08544, USA
| | - Samuel M L Teicher
- Materials Department and Materials Research Laboratory, University of California, Santa Barbara, CA, 93106, USA
| | - Shiming Lei
- Department of Chemistry, Princeton University, Princeton, NJ, 08544, USA
| | - Jason F Khoury
- Department of Chemistry, Princeton University, Princeton, NJ, 08544, USA
| | - 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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159
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Khalifa AM, Kaul RK, Shimshoni E, Fertig HA, Murthy G. Weyl Semimetal Path to Valley Filtering in Graphene. PHYSICAL REVIEW LETTERS 2021; 127:126801. [PMID: 34597113 DOI: 10.1103/physrevlett.127.126801] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/09/2021] [Accepted: 08/23/2021] [Indexed: 06/13/2023]
Abstract
We propose a device in which a sheet of graphene is coupled to a Weyl semimetal, allowing for the physical access to the study of tunneling from two- to three-dimensional massless Dirac fermions. Because of the reconstructed band structure, we find that this device acts as a robust valley filter for electrons in the graphene sheet. We show that, by appropriate alignment, the Weyl semimetal draws away current in one of the two graphene valleys, while allowing current in the other to pass unimpeded. In contrast to other proposed valley filters, the mechanism of our proposed device occurs in the bulk of the graphene sheet, obviating the need for carefully shaped edges or dimensions.
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Affiliation(s)
- Ahmed M Khalifa
- Department of Physics and Astronomy, University of Kentucky, Lexington, Kentucky 40506-0055, USA
| | - Ribhu K Kaul
- Department of Physics and Astronomy, University of Kentucky, Lexington, Kentucky 40506-0055, USA
| | - Efrat Shimshoni
- Department of Physics, Bar-Ilan University, Ramat-Gan 52900, Israel
| | - H A Fertig
- Department of Physics, Indiana University, Bloomington, Indiana 47405, USA
| | - Ganpathy Murthy
- Department of Physics and Astronomy, University of Kentucky, Lexington, Kentucky 40506-0055, USA
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160
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Pandey V, Sihi A, Pandey SK. An ab initiostudy of topological and transport properties of YAuPb. JOURNAL OF PHYSICS. CONDENSED MATTER : AN INSTITUTE OF PHYSICS JOURNAL 2021; 33:475503. [PMID: 34438371 DOI: 10.1088/1361-648x/ac216d] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/02/2021] [Accepted: 08/26/2021] [Indexed: 06/13/2023]
Abstract
In the last few decades, the study of topological materials has been carried out on an extensive scale. Half-Heusler alloys are well known for their topological behaviours. In this work, we present a detailed study of topological properties of a ternary half-Heusler alloy, YAuPb, using the tight-binding approach. We have calculated some important topological properties which includes-finding nodes and their chiralities, Berry curvature (Ω) and the surface-states. Five pairs of characteristic nodes with equal and opposite chiralities are obtained. Based on the study of these properties, we categorise the material as non-trivial topological semimetal. Besides the topological behaviours, we present a comparative study of temperature dependent transport properties corresponding to the chemical potential (μ) of the Fermi level and the node points. The temperature range chosen for the study is 50-300 K. The results obtained from the calculations of electrical conductivity per unit relaxation time (σ/τ) and the electronic part of thermal conductivity per unit relaxation time (κ0) indicates the conducting nature of the material to both the heat and electricity. At the Fermi level, the value of Seebeck coefficient (S) is found to be ∼-9.07(-35.95) μV K-1at 50(300) K. The negative value ofSindicates the n-type behaviour of the compound. The calculated value of electronic specific heat (Pauli magnetic susceptibility) corresponding to Fermi level is ∼0.03(0.18) × 10-2 J mol-1 K-1(∼1.21(1.14) × 10-10 m3 mol-1) at 50(300) K. This work suggests that YAuPb is a promising candidate of non-trivial topological semimetals which can be employed in transmission of heat and electricity, and as n-type material within the temperature range of 50-300 K.
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Affiliation(s)
- Vivek Pandey
- School of Basic Sciences, Indian Institute of Technology Mandi, Kamand-175075, India
| | - Antik Sihi
- School of Basic Sciences, Indian Institute of Technology Mandi, Kamand-175075, India
| | - Sudhir K Pandey
- School of Engineering, Indian Institute of Technology Mandi, Kamand-175075, India
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161
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Zhang P, Ouyang T, Li J, He C, Chen Y, Zhang C, Tang C, Zhong J. Tunable topologically nontrivial states in newly discovered graphyne allotropes: from Dirac nodal grid to Dirac nodal loop. NANOTECHNOLOGY 2021; 32:485705. [PMID: 34380128 DOI: 10.1088/1361-6528/ac1cbe] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/08/2021] [Accepted: 08/09/2021] [Indexed: 06/13/2023]
Abstract
By means of quotient-graph associated crystal prediction method, a new graphyne allotrope with unique Dirac nodal grid state is reported in this work. It is named as 191-E24Y24-1 according to its hexagonal lattice (with P6/mmm symmetry, No. 191) containing 24 sp2-hybridized carbon atoms and 24 sp-hybridized ones. The first-principles results show that the total energy of 191-E24Y24-1 is more favorable than that of recent synthesizedβ-graphdiyne and carbon ene-yne. It is also demonstrated to be dynamically, thermally, and mechanically stable. Interestingly, the 191-E24Y24-1 harbors intrinsic semimetal features showing intriguing hexagonal Dirac nodal grid state in the reciprocal space. Such unique electronic state is stable against small external tensile strains, and it is tunable under compression strains which will transform to new triangle Dirac nodal grid state. Moreover, a new metastable graphyne allotrope named 191-E12Y36-4 with Dirac nodal loop state is also observed in the process of stretching 191-E24Y24-1 with large tensile strains. The results presented in this work reveal two novel graphyne allotropes with exotic electronic properties. These discoveries are not only physical interesting, but also provide potential material candidates for carbon-based high performance electronic nanodevices.
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Affiliation(s)
- Pei Zhang
- Hunan Key Laboratory for Micro-Nano Energy Materials and Device, Xiangtan University, Xiangtan 411105, Hunan, People's Republic of China
- School of Physics and Optoelectronics, Xiangtan University, Xiangtan 411105, Hunan, People's Republic of China
| | - Tao Ouyang
- Hunan Key Laboratory for Micro-Nano Energy Materials and Device, Xiangtan University, Xiangtan 411105, Hunan, People's Republic of China
- School of Physics and Optoelectronics, Xiangtan University, Xiangtan 411105, Hunan, People's Republic of China
| | - Jin Li
- Hunan Key Laboratory for Micro-Nano Energy Materials and Device, Xiangtan University, Xiangtan 411105, Hunan, People's Republic of China
- School of Physics and Optoelectronics, Xiangtan University, Xiangtan 411105, Hunan, People's Republic of China
| | - Chaoyu He
- Hunan Key Laboratory for Micro-Nano Energy Materials and Device, Xiangtan University, Xiangtan 411105, Hunan, People's Republic of China
- School of Physics and Optoelectronics, Xiangtan University, Xiangtan 411105, Hunan, People's Republic of China
| | - Yuanping Chen
- Faculty of Science, Jiangsu University, Zhenjiang, 212013, Jiangsu, People's Republic of China
| | - Chunxiao Zhang
- Hunan Key Laboratory for Micro-Nano Energy Materials and Device, Xiangtan University, Xiangtan 411105, Hunan, People's Republic of China
- School of Physics and Optoelectronics, Xiangtan University, Xiangtan 411105, Hunan, People's Republic of China
| | - Chao Tang
- Hunan Key Laboratory for Micro-Nano Energy Materials and Device, Xiangtan University, Xiangtan 411105, Hunan, People's Republic of China
- School of Physics and Optoelectronics, Xiangtan University, Xiangtan 411105, Hunan, People's Republic of China
| | - Jianxin Zhong
- Hunan Key Laboratory for Micro-Nano Energy Materials and Device, Xiangtan University, Xiangtan 411105, Hunan, People's Republic of China
- School of Physics and Optoelectronics, Xiangtan University, Xiangtan 411105, Hunan, People's Republic of China
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162
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Lin W, Liu L, Liu Q, Li L, Shu X, Li C, Xie Q, Jiang P, Zheng X, Guo R, Lim Z, Zeng S, Zhou G, Wang H, Zhou J, Yang P, Pennycook SJ, Xu X, Zhong Z, Wang Z, Chen J. Electric Field Control of the Magnetic Weyl Fermion in an Epitaxial SrRuO 3 (111) Thin Film. ADVANCED MATERIALS (DEERFIELD BEACH, FLA.) 2021; 33:e2101316. [PMID: 34302392 DOI: 10.1002/adma.202101316] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 02/15/2021] [Revised: 05/17/2021] [Indexed: 06/13/2023]
Abstract
The magnetic Weyl fermion originates from the time reversal symmetry (TRS)-breaking in magnetic crystalline structures, where the topology and magnetism entangle with each other. Therefore, the magnetic Weyl fermion is expected to be effectively tuned by the magnetic field and electrical field, which holds promise for future topologically protected electronics. However, the electrical field control of the magnetic Weyl fermion has rarely been reported, which is prevented by the limited number of identified magnetic Weyl solids. Here, the electric field control of the magnetic Weyl fermion is demonstrated in an epitaxial SrRuO3 (111) thin film. The magnetic Weyl fermion in the SrRuO3 films is indicated by the chiral anomaly induced magnetotransport, and is verified by the observed Weyl nodes in the electronic structures characterized by the angle-resolved photoemission spectroscopy (ARPES) and first-principles calculations. Through the ionic-liquid gating experiment, the effective manipulation of the Weyl fermion by electric field is demonstrated, in terms of the sign-change of the ordinary Hall effect, the nonmonotonic tuning of the anomalous Hall effect, and the observation of the linear magnetoresistance under proper gating voltages. The work may stimulate the searching and tuning of Weyl fermions in other magnetic materials, which are promising in energy-efficient electronics.
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Affiliation(s)
- Weinan Lin
- Department of Materials Science and Engineering, National University of Singapore, Singapore, 117575, Singapore
| | - Liang Liu
- Department of Materials Science and Engineering, National University of Singapore, Singapore, 117575, Singapore
| | - Qing Liu
- Key Laboratory of Magnetic Materials and Devices & Zhejiang Province Key Laboratory of Magnetic Materials and Application Technology, Ningbo Institute of Materials Technology and Engineering, Chinese Academy of Sciences, Ningbo, 315201, China
| | - Lei Li
- Key Laboratory of Magnetic Materials and Devices & Zhejiang Province Key Laboratory of Magnetic Materials and Application Technology, Ningbo Institute of Materials Technology and Engineering, Chinese Academy of Sciences, Ningbo, 315201, China
- Institute of Flexible Electronics, Northwestern Polytechnical University, Xi'an, 710072, China
| | - Xinyu Shu
- Department of Materials Science and Engineering, National University of Singapore, Singapore, 117575, Singapore
| | - Changjian Li
- Department of Materials Science and Engineering, National University of Singapore, Singapore, 117575, Singapore
| | - Qidong Xie
- Department of Materials Science and Engineering, National University of Singapore, Singapore, 117575, Singapore
| | - Peiheng Jiang
- Key Laboratory of Magnetic Materials and Devices & Zhejiang Province Key Laboratory of Magnetic Materials and Application Technology, Ningbo Institute of Materials Technology and Engineering, Chinese Academy of Sciences, Ningbo, 315201, China
| | - Xuan Zheng
- Key Laboratory of Magnetic Materials and Devices & Zhejiang Province Key Laboratory of Magnetic Materials and Application Technology, Ningbo Institute of Materials Technology and Engineering, Chinese Academy of Sciences, Ningbo, 315201, China
- Department of Chemical and Environmental Engineering, The University of Nottingham, Ningbo, 315042, China
| | - Rui Guo
- Department of Materials Science and Engineering, National University of Singapore, Singapore, 117575, Singapore
| | - Zhishiuh Lim
- NUSNNI-Nanocore, National University of Singapore, Singapore, 117411, Singapore
| | - Shengwei Zeng
- NUSNNI-Nanocore, National University of Singapore, Singapore, 117411, Singapore
| | - Guowei Zhou
- Key Laboratory of Magnetic Molecules and Magnetic Information Materials of Ministry of Education, School of Chemistry and Materials Science, Shanxi Normal University, Linfen, 041004, China
| | - Han Wang
- Department of Materials Science and Engineering, National University of Singapore, Singapore, 117575, Singapore
| | - Jing Zhou
- Department of Materials Science and Engineering, National University of Singapore, Singapore, 117575, Singapore
| | - Ping Yang
- Singapore Synchrotron Light Source (SSLS), National University of Singapore, Singapore, 117603, Singapore
| | - Stephen J Pennycook
- Department of Materials Science and Engineering, National University of Singapore, Singapore, 117575, Singapore
| | - Xiaohong Xu
- Key Laboratory of Magnetic Molecules and Magnetic Information Materials of Ministry of Education, School of Chemistry and Materials Science, Shanxi Normal University, Linfen, 041004, China
| | - Zhicheng Zhong
- Key Laboratory of Magnetic Materials and Devices & Zhejiang Province Key Laboratory of Magnetic Materials and Application Technology, Ningbo Institute of Materials Technology and Engineering, Chinese Academy of Sciences, Ningbo, 315201, China
- China Center of Materials Science and Optoelectronics Engineering, University of Chinese Academy of Sciences, Beijing, 100049, China
| | - Zhiming Wang
- Key Laboratory of Magnetic Materials and Devices & Zhejiang Province Key Laboratory of Magnetic Materials and Application Technology, Ningbo Institute of Materials Technology and Engineering, Chinese Academy of Sciences, Ningbo, 315201, China
- China Center of Materials Science and Optoelectronics Engineering, University of Chinese Academy of Sciences, Beijing, 100049, China
| | - Jingsheng Chen
- Department of Materials Science and Engineering, National University of Singapore, Singapore, 117575, Singapore
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163
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Bai T, Ai J, Ma J, Duan Y, Han L, Jiang J, Che S. Resistance‐Chiral Anisotropy of Chiral Mesostructured Half‐metallic Fe
3
O
4
Films. Angew Chem Int Ed Engl 2021. [DOI: 10.1002/ange.202108142] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/10/2022]
Affiliation(s)
- Te Bai
- School of Chemistry and Chemical Engineering State Key Laboratory of Metal Matrix Composites Shanghai Key Laboratory for Molecular Engineering of Chiral Drugs Shanghai Jiao Tong University 800 Dongchuan Road Shanghai 200240 P. R. China
| | - Jing Ai
- School of Chemical Science and Engineering Tongji University 1239 Siping Road Shanghai 200092 P. R. China
| | - Jie Ma
- School of Physics and Astronomy Key Laboratory of Artificial Structures and Quantum Control Ministry of Education Shanghai Jiao Tong University 800 Dongchuan Road Shanghai 200240 P. R. China
| | - Yingying Duan
- School of Chemical Science and Engineering Tongji University 1239 Siping Road Shanghai 200092 P. R. China
| | - Lu Han
- School of Chemical Science and Engineering Tongji University 1239 Siping Road Shanghai 200092 P. R. China
| | - Jingang Jiang
- Shanghai Key Laboratory of Green Chemistry and Chemical Processes School of Chemistry and Molecular Engineering East China Normal University 3663 North Zhongshan Road Shanghai 200062 P. R. China
| | - Shunai Che
- School of Chemistry and Chemical Engineering State Key Laboratory of Metal Matrix Composites Shanghai Key Laboratory for Molecular Engineering of Chiral Drugs Shanghai Jiao Tong University 800 Dongchuan Road Shanghai 200240 P. R. China
- School of Chemical Science and Engineering Tongji University 1239 Siping Road Shanghai 200092 P. R. China
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164
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Hu M, Zhang Y, Jiang X, Qiao T, Wang Q, Zhu S, Xiao M, Liu H. Double-bowl state in photonic Dirac nodal line semimetal. LIGHT, SCIENCE & APPLICATIONS 2021; 10:170. [PMID: 34417438 PMCID: PMC8379272 DOI: 10.1038/s41377-021-00614-6] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/11/2021] [Revised: 08/08/2021] [Accepted: 08/09/2021] [Indexed: 06/03/2023]
Abstract
The past decade has seen a proliferation of topological materials for both insulators and semimetals in electronic systems and classical waves. Topological semimetals exhibit topologically protected band degeneracies, such as nodal points and nodal lines. Dirac nodal line semimetals (DNLS), which own four-fold line degeneracy, have drawn particular attention. DNLSs have been studied in electronic systems but there is no photonic DNLS. Here in this work, we provide a new mechanism, which is unique for photonic systems to investigate a stringent photonic DNLS. When truncated, the photonic DNLS exhibits double-bowl states (DBS), which comprise two sets of perpendicularly polarized surface states. In sharp contrast to nondegenerate surface states in other photonic systems, here the two sets of surface states are almost degenerate over the whole-spectrum range. The DBS and the bulk Dirac nodal ring (DNR) dispersion along the relevant directions, are experimentally resolved.
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Affiliation(s)
- Mengying Hu
- National Laboratory of Solid State Microstructures, School of Physics, Collaborative Innovation Center of Advanced Microstructures, Nanjing University, 210093, Nanjing, China
| | - Ye Zhang
- National Laboratory of Solid State Microstructures, School of Physics, Collaborative Innovation Center of Advanced Microstructures, Nanjing University, 210093, Nanjing, China
| | - Xi Jiang
- National Laboratory of Solid State Microstructures, School of Physics, Collaborative Innovation Center of Advanced Microstructures, Nanjing University, 210093, Nanjing, China
| | - Tong Qiao
- National Laboratory of Solid State Microstructures, School of Physics, Collaborative Innovation Center of Advanced Microstructures, Nanjing University, 210093, Nanjing, China
| | - Qiang Wang
- Division of Physics and Applied Physics, School of Physical and Mathematical Sciences, Nanyang Technological University, Singapore, 637371, Singapore
| | - Shining Zhu
- National Laboratory of Solid State Microstructures, School of Physics, Collaborative Innovation Center of Advanced Microstructures, Nanjing University, 210093, Nanjing, China
| | - Meng Xiao
- Key Laboratory of Artificial Micro- and Nano-structures of Ministry of Education and School of Physics and Technology, Wuhan University, 430072, Wuhan, China.
| | - Hui Liu
- National Laboratory of Solid State Microstructures, School of Physics, Collaborative Innovation Center of Advanced Microstructures, Nanjing University, 210093, Nanjing, China.
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165
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Takahashi S, Tamaki S, Yamashita K, Yamaguchi T, Ueda T, Iwamoto S. Transmission properties of microwaves at an optical Weyl point in a three-dimensional chiral photonic crystal. OPTICS EXPRESS 2021; 29:27127-27136. [PMID: 34615134 DOI: 10.1364/oe.431233] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/19/2021] [Accepted: 07/23/2021] [Indexed: 06/13/2023]
Abstract
Microwave transmission measurements were performed for a three-dimensional (3D) layer-by-layer chiral photonic crystal (PhC), whose photonic band structure contains 3D singular points, Weyl points. For the frequency and wavevector in the vicinity of a Weyl point, the transmitted intensity was found to be inversely proportional to the square of the propagation length. In addition, the transmitted wave was well-collimated in the plane parallel to the PhC layers, even for point-source incidence. When a plane wave was incident on the PhC containing metal scatters, the planar wavefront was reconstructed after the transmission, indicating a cloaking effect.
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166
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Ma S, Bi Y, Guo Q, Yang B, You O, Feng J, Sun HB, Zhang S. Linked Weyl surfaces and Weyl arcs in photonic metamaterials. Science 2021; 373:572-576. [PMID: 34326241 DOI: 10.1126/science.abi7803] [Citation(s) in RCA: 13] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/31/2021] [Accepted: 06/18/2021] [Indexed: 11/02/2022]
Abstract
Generalization of the concept of band topology from lower-dimensional to higher-dimensional (n > 3) physical systems is expected to introduce new bulk and boundary topological effects. However, theoretically predicted topological singularities in five-dimensional systems-Weyl surfaces and Yang monopoles-have either not been demonstrated in realistic physical systems or are limited to purely synthetic dimensions. We constructed a system possessing Yang monopoles and Weyl surfaces based on metamaterials with engineered electromagnetic properties, leading to the observation of several intriguing bulk and surface phenomena, such as linking of Weyl surfaces and surface Weyl arcs, via selected three-dimensional subspaces. The demonstrated photonic Weyl surfaces and Weyl arcs leverage the concept of higher-dimension topology to control the propagation of electromagnetic waves in artificially engineered photonic media.
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Affiliation(s)
- Shaojie Ma
- Department of Physics, University of Hong Kong, Hong Kong, China.,School of Physics and Astronomy, University of Birmingham, Birmingham B15 2TT, UK
| | - Yangang Bi
- Department of Physics, University of Hong Kong, Hong Kong, China.,School of Physics and Astronomy, University of Birmingham, Birmingham B15 2TT, UK.,State Key Laboratory of Integrated Optoelectronics, College of Electronic Science and Engineering, Jilin University, Changchun 130012, China
| | - Qinghua Guo
- Department of Physics and Institute for Advanced Study, The Hong Kong University of Science and Technology, Hong Kong, China
| | - Biao Yang
- College of Advanced Interdisciplinary Studies, National University of Defense Technology, Changsha 410073, China
| | - Oubo You
- Department of Physics, University of Hong Kong, Hong Kong, China.,School of Physics and Astronomy, University of Birmingham, Birmingham B15 2TT, UK
| | - Jing Feng
- State Key Laboratory of Integrated Optoelectronics, College of Electronic Science and Engineering, Jilin University, Changchun 130012, China
| | - Hong-Bo Sun
- State Key Laboratory of Integrated Optoelectronics, College of Electronic Science and Engineering, Jilin University, Changchun 130012, China.,State Key Laboratory of Precision Measurement Technology and Instruments, Department of Precision Instrument, Tsinghua University, Haidian District, Beijing 100084, China
| | - Shuang Zhang
- Department of Physics, University of Hong Kong, Hong Kong, China. .,School of Physics and Astronomy, University of Birmingham, Birmingham B15 2TT, UK.,Department of Electrical and Electronic Engineering, University of Hong Kong, Hong Kong, China
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167
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Howlader S, Sheet G. Tip-induced superconductivity. JOURNAL OF PHYSICS. CONDENSED MATTER : AN INSTITUTE OF PHYSICS JOURNAL 2021; 33:403002. [PMID: 34087817 DOI: 10.1088/1361-648x/ac0850] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 01/13/2021] [Accepted: 06/04/2021] [Indexed: 06/12/2023]
Abstract
It is widely believed that topological superconductivity, a hitherto elusive phase of quantum matter, can be achieved by inducing superconductivity in topological materials. In search of such topological superconductors, certain topological insulators (like, Bi2Se3) were successfully turned into superconductors by metal-ion (Cu, Pd, Sr, Nb etc) intercalation. Superconductivity could be induced in topological materials through applying pressure as well. For example, a pressure-induced superconducting phase was found in the topological insulator Bi2Se3. However, in all such cases, no conclusive signature of topological superconductivity was found. In this review, we will discuss about another novel way of inducing superconductivity in a non-superconducting topological material-by creating a mesoscopic interface on the material with a non-superconducting, normal metallic tip where the mesoscopic interface becomes superconducting. Such a phase is now known as a tip-induced superconducting (TISC) phase. This was first realized on Cd3As2in India. Following that, a large number of other topological materials were shown to display TISC. Since the TISC phase emerges only at a confined region under a mesoscopic point contact, traditional bulk tools for characterizing superconductivity cannot be employed to detect/confirm such a phase. On the other hand, such a point contact geometry is ideal for probing the possible existence of a temperature and magnetic field dependent superconducting energy gap and a temperature and magnetic field dependent critical current. We will review the details of the experimental signatures that can be used to prove the existence of superconductivity even when the 'text-book' tests for detecting superconductivity cannot be performed. Then, we will review various systems where a TISC phase could be realized.
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Affiliation(s)
- Sandeep Howlader
- Department of Physical Sciences, Indian Institute of Science Education and Research Mohali, 81, Knowledge City, SAS Nagar, Manauli 140306, Punjab, India
| | - Goutam Sheet
- Department of Physical Sciences, Indian Institute of Science Education and Research Mohali, 81, Knowledge City, SAS Nagar, Manauli 140306, Punjab, India
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168
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Bai T, Ai J, Ma J, Duan Y, Han L, Jiang J, Che S. Resistance-Chiral Anisotropy of Chiral Mesostructured Half-metallic Fe 3 O 4 Films. Angew Chem Int Ed Engl 2021; 60:20036-20041. [PMID: 34224198 DOI: 10.1002/anie.202108142] [Citation(s) in RCA: 7] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/27/2021] [Indexed: 11/11/2022]
Abstract
Half-metallic materials are theoretically predicted to be metallic and insulating, which have not been confirmed experimentally, and the predictions are still in doubt. We report the resistance-chiral anisotropy (R-ChA), i.e., chirality-dependent electrical conductivity, in chiral mesostructured Fe3 O4 films (CMFFs) grown on the substrates via a hydrothermal method using amino acids as symmetry-breaking agents. Two levels of chirality exist in the CMFFs: primary distortion of the crystal lattice forms twisted nanoflakes, and secondary helical stacking of nanoflakes forms fan-shaped nanoplates. At temperatures below 30 K, the CMFFs exhibited metallic conductivity and insulation for one handedness and the other, respectively. The chirality-dependent effective magnetic fields were speculated to stabilize the opposite spin in the antipodal chiral frame, which led to the free transport of electrons in one handedness of the chiral structure and immobility for the other handedness.
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Affiliation(s)
- Te Bai
- School of Chemistry and Chemical Engineering, State Key Laboratory of Metal Matrix Composites, Shanghai Key Laboratory for Molecular Engineering of Chiral Drugs, Shanghai Jiao Tong University, 800 Dongchuan Road, Shanghai, 200240, P. R. China
| | - Jing Ai
- School of Chemical Science and Engineering, Tongji University, 1239 Siping Road, Shanghai, 200092, P. R. China
| | - Jie Ma
- School of Physics and Astronomy, Key Laboratory of Artificial Structures and Quantum Control, Ministry of Education, Shanghai Jiao Tong University, 800 Dongchuan Road, Shanghai, 200240, P. R. China
| | - Yingying Duan
- School of Chemical Science and Engineering, Tongji University, 1239 Siping Road, Shanghai, 200092, P. R. China
| | - Lu Han
- School of Chemical Science and Engineering, Tongji University, 1239 Siping Road, Shanghai, 200092, P. R. China
| | - Jingang Jiang
- Shanghai Key Laboratory of Green Chemistry and Chemical Processes, School of Chemistry and Molecular Engineering, East China Normal University, 3663 North Zhongshan Road, Shanghai, 200062, P. R. China
| | - Shunai Che
- School of Chemistry and Chemical Engineering, State Key Laboratory of Metal Matrix Composites, Shanghai Key Laboratory for Molecular Engineering of Chiral Drugs, Shanghai Jiao Tong University, 800 Dongchuan Road, Shanghai, 200240, P. R. China.,School of Chemical Science and Engineering, Tongji University, 1239 Siping Road, Shanghai, 200092, P. R. China
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169
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Deng Y, Li P, Zhu C, Zhou J, Wang X, Cui J, Yang X, Tao L, Zeng Q, Duan R, Fu Q, Zhu C, Xu J, Qu F, Yang C, Jing X, Lu L, Liu G, Liu Z. Controlled Synthesis of Mo xW 1-xTe 2 Atomic Layers with Emergent Quantum States. ACS NANO 2021; 15:11526-11534. [PMID: 34162202 DOI: 10.1021/acsnano.1c01441] [Citation(s) in RCA: 6] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/13/2023]
Abstract
Recently, new states of matter like superconducting or topological quantum states were found in transition metal dichalcogenides (TMDs) and manifested themselves in a series of exotic physical behaviors. Such phenomena have been demonstrated to exist in a series of transition metal tellurides including MoTe2, WTe2, and alloyed MoxW1-xTe2. However, the behaviors in the alloy system have been rarely addressed due to their difficulty in obtaining atomic layers with controlled composition, albeit the alloy offers a great platform to tune the quantum states. Here, we report a facile CVD method to synthesize the MoxW1-xTe2 with controllable thickness and chemical composition ratios. The atomic structure of a monolayer MoxW1-xTe2 alloy was experimentally confirmed by scanning transmission electron microscopy. Importantly, two different transport behaviors including superconducting and Weyl semimetal states were observed in Mo-rich Mo0.8W0.2Te2 and W-rich Mo0.2W0.8Te2 samples, respectively. Our results show that the electrical properties of MoxW1-xTe2 can be tuned by controlling the chemical composition, demonstrating our controllable CVD growth method is an efficient strategy to manipulate the physical properties of TMDCs. Meanwhile, it provides a perspective on further comprehension and sheds light on the design of devices with topological multicomponent TMDC materials.
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Affiliation(s)
- Ya Deng
- School of Materials Science & Engineering, Nanyang Technological University, Singapore 639798, Singapore
| | - Peiling Li
- Beijing National Laboratory for Condensed Matter Physics, Institute of Physics, Chinese Academy of Sciences, Beijing 100190, China
- University of Chinese Academy of Sciences, Beijing 100049, China
| | - Chao Zhu
- School of Materials Science & Engineering, Nanyang Technological University, Singapore 639798, Singapore
| | - Jiadong Zhou
- School of Materials Science & Engineering, Nanyang Technological University, Singapore 639798, Singapore
| | - Xiaowei Wang
- School of Materials Science & Engineering, Nanyang Technological University, Singapore 639798, Singapore
| | - Jian Cui
- Beijing National Laboratory for Condensed Matter Physics, Institute of Physics, Chinese Academy of Sciences, Beijing 100190, China
| | - Xue Yang
- Beijing National Laboratory for Condensed Matter Physics, Institute of Physics, Chinese Academy of Sciences, Beijing 100190, China
- University of Chinese Academy of Sciences, Beijing 100049, China
| | - Li Tao
- Department of Electronic Engineering, The Chinese University of Hong Kong, Shatin, N.T., Hong Kong SAR, China
| | - Qingsheng Zeng
- School of Materials Science & Engineering, Nanyang Technological University, Singapore 639798, Singapore
| | - Ruihuan Duan
- School of Materials Science & Engineering, Nanyang Technological University, Singapore 639798, Singapore
| | - Qundong Fu
- School of Materials Science & Engineering, Nanyang Technological University, Singapore 639798, Singapore
| | - Chao Zhu
- School of Materials Science & Engineering, Nanyang Technological University, Singapore 639798, Singapore
| | - Jianbin Xu
- Department of Electronic Engineering, The Chinese University of Hong Kong, Shatin, N.T., Hong Kong SAR, China
| | - Fanming Qu
- Beijing National Laboratory for Condensed Matter Physics, Institute of Physics, Chinese Academy of Sciences, Beijing 100190, China
- University of Chinese Academy of Sciences, Beijing 100049, China
- Songshan Lake Materials Laboratory, Dongguan, Guangdong 523808, China
| | - Changli Yang
- Beijing National Laboratory for Condensed Matter Physics, Institute of Physics, Chinese Academy of Sciences, Beijing 100190, China
- University of Chinese Academy of Sciences, Beijing 100049, China
| | - Xiunian Jing
- Beijing National Laboratory for Condensed Matter Physics, Institute of Physics, Chinese Academy of Sciences, Beijing 100190, China
- Songshan Lake Materials Laboratory, Dongguan, Guangdong 523808, China
| | - Li Lu
- Beijing National Laboratory for Condensed Matter Physics, Institute of Physics, Chinese Academy of Sciences, Beijing 100190, China
- University of Chinese Academy of Sciences, Beijing 100049, China
- Songshan Lake Materials Laboratory, Dongguan, Guangdong 523808, China
| | - Guangtong Liu
- Beijing National Laboratory for Condensed Matter Physics, Institute of Physics, Chinese Academy of Sciences, Beijing 100190, China
- University of Chinese Academy of Sciences, Beijing 100049, China
- Songshan Lake Materials Laboratory, Dongguan, Guangdong 523808, China
| | - Zheng Liu
- CINTRA CNRS/NTU/THALES, UMI 3288, Singapore 637553, Singapore
- School of Materials Science and Engineering, School of Physical and Mathematical Science and School of Electrical and Electronic Engineering, Nanyang Technological University, Singapore 639798, Singapore
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170
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Shao X, Sun L, Ma X, Feng X, Gao H, Ding C, Zhao M. Multiple Dirac cones and Lifshitz transition in a two-dimensional Cairo lattice as a Hawking evaporation analogue. JOURNAL OF PHYSICS. CONDENSED MATTER : AN INSTITUTE OF PHYSICS JOURNAL 2021; 33:365001. [PMID: 34161939 DOI: 10.1088/1361-648x/ac0dd4] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/30/2021] [Accepted: 06/23/2021] [Indexed: 06/13/2023]
Abstract
The linear energy-momentum dispersion of Dirac cones offers a unique platform for mimicking the fantastical phenomena in high energy physics, such as Dirac fermions and black hole (BH) horizons. Three types of Dirac cones (I, III, and II) with different tilts have been proposed individually in specific materials but lack of integral lattice model. Here, we demonstrated the three types of Dirac cones inherited in aπ-conjugated Cairo lattice of double-degeneratedπandpzorbitals by means of tight-binding (TB) approach, which paves a way for the design of two-dimensional (2D) Dirac materials. From first-principles calculations, we predicted a candidate material,penta-NiSb2monolayer, to achieve these multiple Dirac cones and the Lifshitz transition between different Dirac cones driven by external biaxial strain. The coexistence of the three types of Dirac cones renderspenta-NiSb2monolayer a promising 2D fermionic analogue to simulate the event-horizon evaporation with a high Hawking temperature.
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Affiliation(s)
- Xiaofei Shao
- School of Physics, State Key Laboratory of Crystal Materials, Shandong University, Jinan 250100, Shandong, People's Republic of China
| | - Lei Sun
- School of Physics, State Key Laboratory of Crystal Materials, Shandong University, Jinan 250100, Shandong, People's Republic of China
| | - Xikui Ma
- School of Physics, State Key Laboratory of Crystal Materials, Shandong University, Jinan 250100, Shandong, People's Republic of China
| | - Xukun Feng
- School of Physics, State Key Laboratory of Crystal Materials, Shandong University, Jinan 250100, Shandong, People's Republic of China
| | - Han Gao
- School of Physics, State Key Laboratory of Crystal Materials, Shandong University, Jinan 250100, Shandong, People's Republic of China
| | - Chao Ding
- School of Physics, State Key Laboratory of Crystal Materials, Shandong University, Jinan 250100, Shandong, People's Republic of China
| | - Mingwen Zhao
- School of Physics, State Key Laboratory of Crystal Materials, Shandong University, Jinan 250100, Shandong, People's Republic of China
- Collaborative Innovation Center of Light Manipulations and Applications, Shandong Normal University, Jinan 250358, People's Republic of China
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171
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Yan ZW, Wang Q, Xiao M, Zhao YL, Zhu SN, Liu H. Probing Rotated Weyl Physics on Nonlinear Lithium Niobate-on-Insulator Chips. PHYSICAL REVIEW LETTERS 2021; 127:013901. [PMID: 34270295 DOI: 10.1103/physrevlett.127.013901] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 01/22/2021] [Accepted: 05/27/2021] [Indexed: 06/13/2023]
Abstract
Topological photonics, featured by stable topological edge states resistant to perturbations, has been utilized to design robust integrated devices. Here, we present a study exploring the intriguing topological rotated Weyl physics in a 3D parameter space based on quaternary waveguide arrays on lithium niobate-on-insulator (LNOI) chips. Unlike previous works that focus on the Fermi arc surface states of a single Weyl structure, we can experimentally construct arbitrary interfaces between two Weyl structures whose orientations can be freely rotated in the synthetic parameter space. This intriguing system was difficult to realize in usual 3D Weyl semimetals due to lattice mismatch. We found whether the interface can host gapless topological interface states or not is determined by the relative rotational directions of the two Weyl structures. In the experiment, we have probed the local characteristics of the TISs through linear optical transmission and nonlinear second harmonic generation. Our study introduces a novel path to explore topological photonics on LNOI chips and various applications in integrated nonlinear and quantum optics.
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Affiliation(s)
- Zhi-Wei Yan
- National Laboratory of Solid State Microstructures, School of Physics, Collaborative Innovation Center of Advanced Microstructures, Nanjing University, Nanjing 210093, China
| | - Qiang Wang
- Division of Physics and Applied Physics, School of Physical and Mathematical Sciences, Nanyang Technological University, Singapore 637371, Singapore
| | - Meng Xiao
- Key Laboratory of Artificial Micro- and Nano-Structures of Ministry of Education and School of Physics and Technology, Wuhan University, Wuhan 430072, China
| | - Yu-Le Zhao
- National Laboratory of Solid State Microstructures, School of Physics, Collaborative Innovation Center of Advanced Microstructures, Nanjing University, Nanjing 210093, China
| | - Shi-Ning Zhu
- National Laboratory of Solid State Microstructures, School of Physics, Collaborative Innovation Center of Advanced Microstructures, Nanjing University, Nanjing 210093, China
| | - Hui Liu
- National Laboratory of Solid State Microstructures, School of Physics, Collaborative Innovation Center of Advanced Microstructures, Nanjing University, Nanjing 210093, China
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172
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Song ZD, Lian B, Queiroz R, Ilan R, Bernevig BA, Stern A. Delocalization Transition of a Disordered Axion Insulator. PHYSICAL REVIEW LETTERS 2021; 127:016602. [PMID: 34270311 DOI: 10.1103/physrevlett.127.016602] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 11/06/2020] [Accepted: 05/30/2021] [Indexed: 06/13/2023]
Abstract
The axion insulator is a higher-order topological insulator protected by inversion symmetry. We show that, under quenched disorder respecting inversion symmetry on average, the topology of the axion insulator stays robust, and an intermediate metallic phase in which states are delocalized is unavoidable at the transition from an axion insulator to a trivial insulator. We derive this conclusion from general arguments, from classical percolation theory, and from the numerical study of a 3D quantum network model simulating a disordered axion insulator through a layer construction. We find the localization length critical exponent near the delocalization transition to be ν=1.42±0.12. We further show that this delocalization transition is stable even to weak breaking of the average inversion symmetry, up to a critical strength. We also quantitatively map our quantum network model to an effective Hamiltonian and we find its low-energy k·p expansion.
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Affiliation(s)
- Zhi-Da Song
- Department of Physics, Princeton University, Princeton, New Jersey 08544, USA
| | - Biao Lian
- Department of Physics, Princeton University, Princeton, New Jersey 08544, USA
| | - Raquel Queiroz
- Department of Condensed Matter Physics, Weizmann Institute of Science, Rehovot 7610001, Israel
| | - Roni Ilan
- Raymond and Beverly Sackler School of Physics and Astronomy, Tel Aviv University, Tel Aviv 69978, Israel
| | - B Andrei Bernevig
- Department of Physics, Princeton University, Princeton, New Jersey 08544, USA
- Physics Department, Freie Universitat Berlin, Arnimallee 14, 14195 Berlin, Germany
- Max Planck Institute of Microstructure Physics, 06120 Halle, Germany
| | - Ady Stern
- Department of Condensed Matter Physics, Weizmann Institute of Science, Rehovot 7610001, Israel
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173
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Lei S, Teicher SML, Topp A, Cai K, Lin J, Cheng G, Salters TH, Rodolakis F, McChesney JL, Lapidus S, Yao N, Krivenkov M, Marchenko D, Varykhalov A, Ast CR, Car R, Cano J, Vergniory MG, Ong NP, Schoop LM. Band Engineering of Dirac Semimetals Using Charge Density Waves. ADVANCED MATERIALS (DEERFIELD BEACH, FLA.) 2021; 33:e2101591. [PMID: 34137086 DOI: 10.1002/adma.202101591] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 02/25/2021] [Revised: 04/03/2021] [Indexed: 06/12/2023]
Abstract
New developments in the field of topological matter are often driven by materials discovery, including novel topological insulators, Dirac semimetals, and Weyl semimetals. In the last few years, large efforts have been made to classify all known inorganic materials with respect to their topology. Unfortunately, a large number of topological materials suffer from non-ideal band structures. For example, topological bands are frequently convoluted with trivial ones, and band structure features of interest can appear far below the Fermi level. This leaves just a handful of materials that are intensively studied. Finding strategies to design new topological materials is a solution. Here, a new mechanism is introduced, which is based on charge density waves and non-symmorphic symmetry, to design an idealized Dirac semimetal. It is then shown experimentally that the antiferromagnetic compound GdSb0.46 Te1.48 is a nearly ideal Dirac semimetal based on the proposed mechanism, meaning that most interfering bands at the Fermi level are suppressed. Its highly unusual transport behavior points to a thus far unknown regime, in which Dirac carriers with Fermi energy very close to the node seem to gradually localize in the presence of lattice and magnetic disorder.
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Affiliation(s)
- Shiming Lei
- 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
| | - Andreas Topp
- Max-Planck-Institut für Festkörperforschung, 70569, Stuttgart, Germany
| | - Kehan Cai
- Department of Chemistry, Princeton University, Princeton, NJ, 08544, USA
| | - Jingjing Lin
- Department of Physics, Princeton University, Princeton, NJ, 08544, USA
| | - Guangming Cheng
- Princeton Institute for The Science and Technology of Materials, Princeton, NJ, 08544, USA
| | - Tyger H Salters
- Department of Chemistry, Princeton University, Princeton, NJ, 08544, USA
| | - Fanny Rodolakis
- Argonne National Laboratory, 9700 South Cass Avenue, Argonne, IL, 60439, USA
| | - Jessica L McChesney
- Argonne National Laboratory, 9700 South Cass Avenue, Argonne, IL, 60439, USA
| | - Saul Lapidus
- Argonne National Laboratory, 9700 South Cass Avenue, Argonne, IL, 60439, USA
| | - Nan Yao
- Princeton Institute for The Science and Technology of Materials, Princeton, NJ, 08544, USA
| | - Maxim Krivenkov
- Helmholtz-Zentrum Berlin für Materialien und Energie, Elektronenspeicherring BESSY II, Albert-Einstein-Straße 15, 12489, Berlin, Germany
| | - Dmitry Marchenko
- Helmholtz-Zentrum Berlin für Materialien und Energie, Elektronenspeicherring BESSY II, Albert-Einstein-Straße 15, 12489, Berlin, Germany
| | - Andrei Varykhalov
- Helmholtz-Zentrum Berlin für Materialien und Energie, Elektronenspeicherring BESSY II, Albert-Einstein-Straße 15, 12489, Berlin, Germany
| | - Christian R Ast
- Max-Planck-Institut für Festkörperforschung, 70569, Stuttgart, Germany
| | - Roberto Car
- Department of Chemistry, Princeton University, Princeton, NJ, 08544, USA
- Department of Physics, Princeton University, Princeton, NJ, 08544, USA
| | - Jennifer Cano
- Department of Physics and Astronomy, Stony Brook University, Stony Brook, NY, 11974, USA
- Center for Computational Quantum Physics, The Flatiron Institute, New York, NY, 10010, USA
| | - Maia G Vergniory
- Donostia International Physics Center, 20018 Donostia-San Sebastian, Spain and IKERBASQUE, Basque Foundation for Science, Maria Diaz de Haro 3, Bilbao, 48013, Spain
| | - 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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174
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Li R, Lv B, Tao H, Shi J, Chong Y, Zhang B, Chen H. Ideal type-II Weyl points in topological circuits. Natl Sci Rev 2021; 8:nwaa192. [PMID: 34691684 PMCID: PMC8310763 DOI: 10.1093/nsr/nwaa192] [Citation(s) in RCA: 12] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/25/2019] [Revised: 05/19/2020] [Accepted: 08/19/2020] [Indexed: 11/21/2022] Open
Abstract
Weyl points (WPs), nodal degenerate points in three-dimensional (3D) momentum space, are said to be 'ideal' if they are symmetry-related and well-separated, and reside at the same energy and far from nontopological bands. Although type-II WPs have unique spectral characteristics compared with type-I counterparts, ideal type-II WPs have not yet been reported because of a lack of an experimental platform with enough flexibility to produce strongly tilted dispersion bands. Here, we experimentally realize a topological circuit that hosts only topological bands with a minimal number of four ideal type-II WPs. By stacking two-dimensional (2D) layers of inductor-capacitor (LC) resonator dimers with the broken parity inversion symmetry (P), we achieve a strongly tilted band structure with two group velocities in the same direction, and topological surface states in an incomplete bandgap. Our results establish an ideal system for the further study of Weyl physics and other exotic topological phenomena.
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Affiliation(s)
- Rujiang Li
- Interdisciplinary Center for Quantum Information, State Key Laboratory of Modern Optical Instrumentation, College of Information Science and Electronic Engineering, Zhejiang University, Hangzhou 310027, China
- ZJU-Hangzhou Global Science and Technology Innovation Center, Key Laboratory of Advanced Micro/Nano Electronic Devices & Smart Systems of Zhejiang, Zhejiang University, Hangzhou 310027, China
| | - Bo Lv
- Key Laboratory of In-Fiber Integrated Optics of Ministry of Education, College of Physics and Optoelectronic Engineering, Harbin Engineering University, Harbin 150001, China
| | - Huibin Tao
- School of Software Engineering, Xi’an Jiaotong University, Xi’an 710054, China
| | - Jinhui Shi
- Key Laboratory of In-Fiber Integrated Optics of Ministry of Education, College of Physics and Optoelectronic Engineering, Harbin Engineering University, Harbin 150001, China
| | - Yidong Chong
- Division of Physics and Applied Physics, School of Physical and Mathematical Sciences, Nanyang Technological University, Singapore 637371, Singapore
- Centre for Disruptive Photonic Technologies, Nanyang Technological University, Singapore 637371, Singapore
| | - Baile Zhang
- Division of Physics and Applied Physics, School of Physical and Mathematical Sciences, Nanyang Technological University, Singapore 637371, Singapore
- Centre for Disruptive Photonic Technologies, Nanyang Technological University, Singapore 637371, Singapore
| | - Hongsheng Chen
- Interdisciplinary Center for Quantum Information, State Key Laboratory of Modern Optical Instrumentation, College of Information Science and Electronic Engineering, Zhejiang University, Hangzhou 310027, China
- ZJU-Hangzhou Global Science and Technology Innovation Center, Key Laboratory of Advanced Micro/Nano Electronic Devices & Smart Systems of Zhejiang, Zhejiang University, Hangzhou 310027, China
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175
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The Axial Anomaly in Lorentz Violating Theories: Towards the Electromagnetic Response of Weakly Tilted Weyl Semimetals. Symmetry (Basel) 2021. [DOI: 10.3390/sym13071181] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/16/2022] Open
Abstract
Using the path integral formulation in Euclidean space, we extended the calculation of the abelian chiral anomalies in the case of Lorentz violating theories by considering a new fermionic correction term provided by the standard model extension, which arises in the continuous Hamiltonian of a weakly tilted Weyl semimetal, and whose cones have opposite tilting. We found that this anomaly is insensitive to the tilting parameter, retaining its well-known covariant form. This independence on the Lorentz violating parameters is consistent with other findings reported in the literature. The initially imposed gauge invariant regularization was consistently recovered at the end of the calculation by the appearance of highly non-trivial combinations of the covariant derivatives, which ultimately managed to give only terms containing the electromagnetic tensor. We emphasize that the value of the anomaly with an arbitrary parameter is not automatically related to the effective action describing the electromagnetic response of such materials.
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176
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Observation of a singular Weyl point surrounded by charged nodal walls in PtGa. Nat Commun 2021; 12:3994. [PMID: 34183664 PMCID: PMC8239007 DOI: 10.1038/s41467-021-24289-0] [Citation(s) in RCA: 6] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/15/2020] [Accepted: 06/10/2021] [Indexed: 11/08/2022] Open
Abstract
Constrained by the Nielsen-Ninomiya no-go theorem, in all so-far experimentally determined Weyl semimetals (WSMs) the Weyl points (WPs) always appear in pairs in the momentum space with no exception. As a consequence, Fermi arcs occur on surfaces which connect the projections of the WPs with opposite chiral charges. However, this situation can be circumvented in the case of unpaired WP, without relevant surface Fermi arc connecting its surface projection, appearing singularly, while its Berry curvature field is absorbed by nontrivial charged nodal walls. Here, combining angle-resolved photoemission spectroscopy with density functional theory calculations, we show experimentally that a singular Weyl point emerges in PtGa at the center of the Brillouin zone (BZ), which is surrounded by closed Weyl nodal walls located at the BZ boundaries and there is no Fermi arc connecting its surface projection. Our results reveal that nontrivial band crossings of different dimensionalities can emerge concomitantly in condensed matter, while their coexistence ensures the net topological charge of different dimensional topological objects to be zero. Our observation extends the applicable range of the original Nielsen-Ninomiya no-go theorem which was derived from zero dimensional paired WPs with opposite chirality.
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177
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Wang R, Peng Z, Wu P, Lu J, Rood MJ, Sun H, Zeng J, Wang Y, Yan Z. Direct Synthesis of Nanosheet-Stacked Hierarchical "Honey Stick-like" MFI Zeolites by an Aromatic Heterocyclic Dual-Functional Organic Structure-Directing Agent. Chemistry 2021; 27:8694-8697. [PMID: 33938064 DOI: 10.1002/chem.202100701] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/25/2021] [Indexed: 11/08/2022]
Abstract
Soft template designing is the most promising strategy for the synthesis of zeolite nanosheets. MFI nanosheets directed by soft templates (containing long-chain alkyl groups or aromatic groups as hydrophobic component) can be found frequently; however, so far, MFI nanosheets synthesized by soft templates with aromatic heterocycle groups (e. g., s-triazine groups) are rare. Herein, a nanosheet-stacked hierarchical MFI zeolite (NSHM) has been synthesized by using a triply branched s-triazine-based surfactant as a bifunctional organic structure-directing agent. On the basis of a geometrical match relationship, a formation model has been proposed. Synthesized NSHM had abundant mesopores stacked by nanosheets and exhibited a high surface area (430 m2 ⋅ g-1 ). The 1 wt% Pd/NSHM attained a significant increase in yield of cyclohexanol/cyclohexanone mixture (from 66 to 85 %) in the oxidation of cyclohexane compared with Silicalite-1 and SBA-15 as supports.
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Affiliation(s)
- Risheng Wang
- College of Science, State Key Laboratory of Heavy Oil Processing, China University of Petroleum (EastChina), No. 66, Changjiang West Road Qingdao Economic & Technical Development Zone, Qingdao, 266580, Shandong, P. R. China
| | - Zhihua Peng
- College of Science, State Key Laboratory of Heavy Oil Processing, China University of Petroleum (EastChina), No. 66, Changjiang West Road Qingdao Economic & Technical Development Zone, Qingdao, 266580, Shandong, P. R. China
| | - Pingping Wu
- College of Science, State Key Laboratory of Heavy Oil Processing, China University of Petroleum (EastChina), No. 66, Changjiang West Road Qingdao Economic & Technical Development Zone, Qingdao, 266580, Shandong, P. R. China
| | - Jinzhi Lu
- College of Science, State Key Laboratory of Heavy Oil Processing, China University of Petroleum (EastChina), No. 66, Changjiang West Road Qingdao Economic & Technical Development Zone, Qingdao, 266580, Shandong, P. R. China
| | - Mark J Rood
- Department of Civil and Environmental Engineering, University of Illinois, 205 North Mathews Avenue, Urbana, Illinois, 61801, United States
| | - Hongman Sun
- College of Science, State Key Laboratory of Heavy Oil Processing, China University of Petroleum (EastChina), No. 66, Changjiang West Road Qingdao Economic & Technical Development Zone, Qingdao, 266580, Shandong, P. R. China
| | - Jingbin Zeng
- College of Science, State Key Laboratory of Heavy Oil Processing, China University of Petroleum (EastChina), No. 66, Changjiang West Road Qingdao Economic & Technical Development Zone, Qingdao, 266580, Shandong, P. R. China
| | - Youhe Wang
- College of Science, State Key Laboratory of Heavy Oil Processing, China University of Petroleum (EastChina), No. 66, Changjiang West Road Qingdao Economic & Technical Development Zone, Qingdao, 266580, Shandong, P. R. China
| | - Zifeng Yan
- College of Science, State Key Laboratory of Heavy Oil Processing, China University of Petroleum (EastChina), No. 66, Changjiang West Road Qingdao Economic & Technical Development Zone, Qingdao, 266580, Shandong, P. R. China
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178
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Wang Q, Ge Y, Sun HX, Xue H, Jia D, Guan YJ, Yuan SQ, Zhang B, Chong YD. Vortex states in an acoustic Weyl crystal with a topological lattice defect. Nat Commun 2021; 12:3654. [PMID: 34135328 PMCID: PMC8209201 DOI: 10.1038/s41467-021-23963-7] [Citation(s) in RCA: 13] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/11/2020] [Accepted: 05/19/2021] [Indexed: 11/09/2022] Open
Abstract
Crystalline materials can host topological lattice defects that are robust against local deformations, and such defects can interact in interesting ways with the topological features of the underlying band structure. We design and implement a three dimensional acoustic Weyl metamaterial hosting robust modes bound to a one-dimensional topological lattice defect. The modes are related to topological features of the bulk bands, and carry nonzero orbital angular momentum locked to the direction of propagation. They span a range of axial wavenumbers defined by the projections of two bulk Weyl points to a one-dimensional subspace, in a manner analogous to the formation of Fermi arc surface states. We use acoustic experiments to probe their dispersion relation, orbital angular momentum locked waveguiding, and ability to emit acoustic vortices into free space. These results point to new possibilities for creating and exploiting topological modes in three-dimensional structures through the interplay between band topology in momentum space and topological lattice defects in real space.
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Affiliation(s)
- Qiang Wang
- Division of Physics and Applied Physics, School of Physical and Mathematical Sciences, Nanyang Technological University, Singapore, Singapore
| | - Yong Ge
- Research Center of Fluid Machinery Engineering and Technology, School of Physics and Electronic Engineering, Jiangsu University, Zhenjiang, China
| | - Hong-Xiang Sun
- Research Center of Fluid Machinery Engineering and Technology, School of Physics and Electronic Engineering, Jiangsu University, Zhenjiang, China
| | - Haoran Xue
- Division of Physics and Applied Physics, School of Physical and Mathematical Sciences, Nanyang Technological University, Singapore, Singapore
| | - Ding Jia
- Research Center of Fluid Machinery Engineering and Technology, School of Physics and Electronic Engineering, Jiangsu University, Zhenjiang, China
| | - Yi-Jun Guan
- Research Center of Fluid Machinery Engineering and Technology, School of Physics and Electronic Engineering, Jiangsu University, Zhenjiang, China
| | - Shou-Qi Yuan
- Research Center of Fluid Machinery Engineering and Technology, School of Physics and Electronic Engineering, Jiangsu University, Zhenjiang, China.
| | - Baile Zhang
- Division of Physics and Applied Physics, School of Physical and Mathematical Sciences, Nanyang Technological University, Singapore, Singapore.
- Centre for Disruptive Photonic Technologies, Nanyang Technological University, Singapore, Singapore.
| | - Y D Chong
- Division of Physics and Applied Physics, School of Physical and Mathematical Sciences, Nanyang Technological University, Singapore, Singapore.
- Centre for Disruptive Photonic Technologies, Nanyang Technological University, Singapore, Singapore.
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179
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Ünzelmann M, Bentmann H, Figgemeier T, Eck P, Neu JN, Geldiyev B, Diekmann F, Rohlf S, Buck J, Hoesch M, Kalläne M, Rossnagel K, Thomale R, Siegrist T, Sangiovanni G, Sante DD, Reinert F. Momentum-space signatures of Berry flux monopoles in the Weyl semimetal TaAs. Nat Commun 2021; 12:3650. [PMID: 34131129 PMCID: PMC8206138 DOI: 10.1038/s41467-021-23727-3] [Citation(s) in RCA: 7] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/01/2020] [Accepted: 05/12/2021] [Indexed: 11/16/2022] Open
Abstract
Since the early days of Dirac flux quantization, magnetic monopoles have been sought after as a potential corollary of quantized electric charge. As opposed to magnetic monopoles embedded into the theory of electromagnetism, Weyl semimetals (WSM) exhibit Berry flux monopoles in reciprocal parameter space. As a function of crystal momentum, such monopoles locate at the crossing point of spin-polarized bands forming the Weyl cone. Here, we report momentum-resolved spectroscopic signatures of Berry flux monopoles in TaAs as a paradigmatic WSM. We carried out angle-resolved photoelectron spectroscopy at bulk-sensitive soft X-ray energies (SX-ARPES) combined with photoelectron spin detection and circular dichroism. The experiments reveal large spin- and orbital-angular-momentum (SAM and OAM) polarizations of the Weyl-fermion states, resulting from the broken crystalline inversion symmetry in TaAs. Supported by first-principles calculations, our measurements image signatures of a topologically non-trivial winding of the OAM at the Weyl nodes and unveil a chirality-dependent SAM of the Weyl bands. Our results provide directly bulk-sensitive spectroscopic support for the non-trivial band topology in the WSM TaAs, promising to have profound implications for the study of quantum-geometric effects in solids. Weyl semimetals exhibit Berry flux monopoles in momentum-space, but direct experimental evidence has remained elusive. Here, the authors reveal topologically non-trivial winding of the orbital-angular-momentum at the Weyl nodes and a chirality-dependent spin-angular-momentum of the Weyl bands, as a direct signature of the Berry flux monopoles in TaAs.
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Affiliation(s)
- M Ünzelmann
- Experimentelle Physik VII and Würzburg-Dresden Cluster of Excellence ct.qmat, Universität Würzburg, Würzburg, Germany
| | - H Bentmann
- Experimentelle Physik VII and Würzburg-Dresden Cluster of Excellence ct.qmat, Universität Würzburg, Würzburg, Germany.
| | - T Figgemeier
- Experimentelle Physik VII and Würzburg-Dresden Cluster of Excellence ct.qmat, Universität Würzburg, Würzburg, Germany
| | - P Eck
- Theoretische Physik I, Universität Würzburg, Würzburg, Germany
| | - J N Neu
- Department of Chemical and Biomedical Engineering, FAMU-FSU College of Engineering, Tallahassee, FL, USA.,National High Magnetic Field Laboratory, Tallahassee, FL, USA
| | - B Geldiyev
- Experimentelle Physik VII and Würzburg-Dresden Cluster of Excellence ct.qmat, Universität Würzburg, Würzburg, Germany
| | - F Diekmann
- Institut für Experimentelle und Angewandte Physik, Christian-Albrechts-Universität zu Kiel, Kiel, Germany.,Ruprecht Haensel Laboratory, Kiel University and DESY, Kiel, Germany
| | - S Rohlf
- Institut für Experimentelle und Angewandte Physik, Christian-Albrechts-Universität zu Kiel, Kiel, Germany.,Ruprecht Haensel Laboratory, Kiel University and DESY, Kiel, Germany
| | - J Buck
- Institut für Experimentelle und Angewandte Physik, Christian-Albrechts-Universität zu Kiel, Kiel, Germany.,Ruprecht Haensel Laboratory, Kiel University and DESY, Kiel, Germany
| | - M Hoesch
- Deutsches Elektronen-Synchrotron DESY, Hamburg, Germany
| | - M Kalläne
- Institut für Experimentelle und Angewandte Physik, Christian-Albrechts-Universität zu Kiel, Kiel, Germany.,Ruprecht Haensel Laboratory, Kiel University and DESY, Kiel, Germany
| | - K Rossnagel
- Institut für Experimentelle und Angewandte Physik, Christian-Albrechts-Universität zu Kiel, Kiel, Germany.,Ruprecht Haensel Laboratory, Kiel University and DESY, Kiel, Germany.,Deutsches Elektronen-Synchrotron DESY, Hamburg, Germany
| | - R Thomale
- Theoretische Physik I, Universität Würzburg, Würzburg, Germany
| | - T Siegrist
- Department of Chemical and Biomedical Engineering, FAMU-FSU College of Engineering, Tallahassee, FL, USA.,National High Magnetic Field Laboratory, Tallahassee, FL, USA
| | - G Sangiovanni
- Theoretische Physik I, Universität Würzburg, Würzburg, Germany
| | - D Di Sante
- Theoretische Physik I, Universität Würzburg, Würzburg, Germany.,Department of Physics and Astronomy, University of Bologna, Bologna, Italy.,Center for Computational Quantum Physics, Flatiron Institute, New York, NY, USA
| | - F Reinert
- Experimentelle Physik VII and Würzburg-Dresden Cluster of Excellence ct.qmat, Universität Würzburg, Würzburg, Germany
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180
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Jung J, Odobesko A, Boshuis R, Szczerbakow A, Story T, Bode M. Systematic Investigation of the Coupling between One-Dimensional Edge States of a Topological Crystalline Insulator. PHYSICAL REVIEW LETTERS 2021; 126:236402. [PMID: 34170152 DOI: 10.1103/physrevlett.126.236402] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 02/15/2021] [Accepted: 05/18/2021] [Indexed: 06/13/2023]
Abstract
The interaction of spin-polarized one-dimensional (1D) topological edge modes localized along single-atomic steps of the topological crystalline insulator Pb_{0.7}Sn_{0.3}Se(001) has been studied systematically by scanning tunneling spectroscopy. Our results reveal that the coupling of adjacent edge modes sets in at a step-to-step distance d_{ss}≤25 nm, resulting in a characteristic splitting of a single peak at the Dirac point in tunneling spectra. Whereas the energy splitting exponentially increases with decreasing d_{ss} for single-atomic steps running almost parallel, we find no splitting for single-atomic step edges under an angle of 90°. The results are discussed in terms of overlapping wave functions with p_{x}, p_{y} orbital character.
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Affiliation(s)
- Johannes Jung
- Physikalisches Institut, Experimentelle Physik II, Universität Würzburg, Am Hubland, 97074 Würzburg, Germany
| | - Artem Odobesko
- Physikalisches Institut, Experimentelle Physik II, Universität Würzburg, Am Hubland, 97074 Würzburg, Germany
| | - Robin Boshuis
- Physikalisches Institut, Experimentelle Physik II, Universität Würzburg, Am Hubland, 97074 Würzburg, Germany
| | - Andrzej Szczerbakow
- Institute of Physics, Polish Academy of Sciences, Aleja Lotników 32/46, 02-668 Warsaw, Poland
| | - Tomasz Story
- Institute of Physics, Polish Academy of Sciences, Aleja Lotników 32/46, 02-668 Warsaw, Poland
- International Research Centre MagTop, Institute of Physics, Polish Academy of Sciences, Aleja Lotnikow 32/46, 02-668 Warsaw, Poland
| | - Matthias Bode
- Physikalisches Institut, Experimentelle Physik II, Universität Würzburg, Am Hubland, 97074 Würzburg, Germany
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181
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Liu X, Yue C, Erohin SV, Zhu Y, Joshy A, Liu J, Sanchez AM, Graf D, Sorokin PB, Mao Z, Hu J, Wei J. Quantum Transport of the 2D Surface State in a Nonsymmorphic Semimetal. NANO LETTERS 2021; 21:4887-4893. [PMID: 33834787 PMCID: PMC8193637 DOI: 10.1021/acs.nanolett.0c04946] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 12/16/2020] [Revised: 04/03/2021] [Indexed: 05/30/2023]
Abstract
In a topological semimetal with Dirac or Weyl points, the bulk-boundary correspondence principle predicts a gapless edge mode if the essential symmetry is still preserved at the surface. The detection of such topological surface state has been considered as the fingerprint prove for crystals with nontrivial topological bulk band. On the contrary, it has been proposed that even with symmetry broken at the surface, a new surface band can emerge in nonsymmorphic topological semimetals. The symmetry reduction at the surface lifts the bulk band degeneracies and produces an unusual "floating" surface band with trivial topology. Here, we first report quantum transport probing to ZrSiSe thin flakes and directly reveal transport signatures of this new surface state. Remarkably, though topologically trivial, such a surface band exhibits substantial two-dimensional Shubnikov-de Haas quantum oscillations with high mobility, which signifies a new protection mechanism and may open applications for quantum computing and spintronic devices.
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Affiliation(s)
- Xue Liu
- Institutes
of Physical Science and Information Technology, Anhui University, Hefei 230601, China
- Department
of Physics and Engineering Physics, Tulane
University, New Orleans, Louisiana 70118, United States
| | - Chunlei Yue
- Department
of Physics and Engineering Physics, Tulane
University, New Orleans, Louisiana 70118, United States
| | - Sergey V. Erohin
- National
University of Science and Technology “MISIS”, Leninsky Prospect 4, Moscow 119049, Russian Federation
- Moscow
Institute of Physics and Technology (State University), 9 Institutskiy per., Dolgoprudny, Moscow Region 141701, Russian Federation
| | - Yanglin Zhu
- Department
of Physics and Engineering Physics, Tulane
University, New Orleans, Louisiana 70118, United States
| | - Abin Joshy
- Department
of Physics and Engineering Physics, Tulane
University, New Orleans, Louisiana 70118, United States
| | - Jinyu Liu
- Department
of Physics and Engineering Physics, Tulane
University, New Orleans, Louisiana 70118, United States
| | - Ana M Sanchez
- Department
of Physics, University of Warwick, Coventry CV4 7AL, United Kingdom
| | - David Graf
- National
High Magnetic Field Lab, Tallahassee, Florida 32310, United States
| | - Pavel B. Sorokin
- National
University of Science and Technology “MISIS”, Leninsky Prospect 4, Moscow 119049, Russian Federation
- Moscow
Institute of Physics and Technology (State University), 9 Institutskiy per., Dolgoprudny, Moscow Region 141701, Russian Federation
| | - Zhiqiang Mao
- Department
of Physics and Engineering Physics, Tulane
University, New Orleans, Louisiana 70118, United States
- Department
of Physics, Pennsylvania State University, University Park, Pennsylvania 16802, United States
| | - Jin Hu
- Department
of Physics, Institute for Nanoscience and Engineering, University of Arkansas, Fayetteville, Arkansas 72701, United States
| | - Jiang Wei
- Department
of Physics and Engineering Physics, Tulane
University, New Orleans, Louisiana 70118, United States
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182
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Suo P, Zhang H, Yan S, Zhang W, Fu J, Lin X, Hao S, Jin Z, Zhang Y, Zhang C, Miao F, Liang SJ, Ma G. Observation of Negative Terahertz Photoconductivity in Large Area Type-II Dirac Semimetal PtTe_{2}. PHYSICAL REVIEW LETTERS 2021; 126:227402. [PMID: 34152189 DOI: 10.1103/physrevlett.126.227402] [Citation(s) in RCA: 15] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/07/2020] [Revised: 02/04/2021] [Accepted: 04/21/2021] [Indexed: 06/13/2023]
Abstract
As a newly emergent type-II Dirac semimetal, platinum telluride (PtTe_{2}) stands out from other two dimensional noble-transition-metal dichalcogenides for the unique band structure and novel physical properties, and has been studied extensively. However, the ultrafast response of low energy quasiparticle excitation in terahertz frequency remains nearly unexplored yet. Herein, we employ optical pump-terahertz probe (OPTP) spectroscopy to systematically study the photocarrier dynamics of PtTe_{2} thin films with varying pump fluence, temperature, and film thickness. Upon photoexcitation the terahertz photoconductivity (PC) of PtTe_{2} films shows abrupt increase initially, while the terahertz PC changes into negative value in a subpicosecond timescale, followed by a prolonged recovery process that lasted a few nanoseconds. The magnitude of both positive and negative terahertz PC response shows strongly pump fluence dependence. We assign the unusual negative terahertz PC to the formation of small polaron due to the strong electron-phonon (e-ph) coupling, which is further substantiated by temperature and film thickness dependent measurements. Moreover, our investigations give a subpicosecond timescale of simultaneous carrier cooling and polaron formation. The present study provides deep insights into the underlying dynamics evolution mechanisms of photocarrier in type-II Dirac semimetal upon photoexcitation, which is of crucial importance for designing PtTe_{2}-based optoelectronic devices.
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Affiliation(s)
- Peng Suo
- Department of Physics, Shanghai University, Shanghai 200444, China
| | - Huiyun Zhang
- College of Electronics and Information Engineering, Shandong University of Science and Technology, Qingdao 266590, China
| | - Shengnan Yan
- Institute of Brain-inspired Intelligence, National Laboratory of Solid State Microstructures, School of Physics, Collaborative Innovation Center of Advanced Microstructures, Nanjing University, Nanjing, 210093, China
| | - Wenjie Zhang
- Department of Physics, Shanghai University, Shanghai 200444, China
| | - Jibo Fu
- Department of Physics, Shanghai University, Shanghai 200444, China
| | - Xian Lin
- Department of Physics, Shanghai University, Shanghai 200444, China
| | - Song Hao
- Institute of Brain-inspired Intelligence, National Laboratory of Solid State Microstructures, School of Physics, Collaborative Innovation Center of Advanced Microstructures, Nanjing University, Nanjing, 210093, China
| | - Zuanming Jin
- Terahertz Technology Innovation Research Institute, Terahertz Spectrum and Imaging Technology Cooperative Innovation Center, Shanghai Key Lab of Modern Optical System, University of Shanghai for Science and Technology, 516 JunGong Road, Shanghai 200093, China
- STU & SIOM Joint Laboratory for Superintense Lasers and the Applications, Shanghai 201210, China
| | - Yuping Zhang
- College of Electronics and Information Engineering, Shandong University of Science and Technology, Qingdao 266590, China
| | - Chao Zhang
- School of Physics, University of Wollongong, Wollongong, New South Wales 2522, Australia
| | - Feng Miao
- Institute of Brain-inspired Intelligence, National Laboratory of Solid State Microstructures, School of Physics, Collaborative Innovation Center of Advanced Microstructures, Nanjing University, Nanjing, 210093, China
| | - Shi-Jun Liang
- Institute of Brain-inspired Intelligence, National Laboratory of Solid State Microstructures, School of Physics, Collaborative Innovation Center of Advanced Microstructures, Nanjing University, Nanjing, 210093, China
| | - Guohong Ma
- Department of Physics, Shanghai University, Shanghai 200444, China
- STU & SIOM Joint Laboratory for Superintense Lasers and the Applications, Shanghai 201210, China
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183
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Li Y, Oh T, Son J, Song J, Kim MK, Song D, Kim S, Chang SH, Kim C, Yang BJ, Noh TW. Correlated Magnetic Weyl Semimetal State in Strained Pr 2 Ir 2 O 7. ADVANCED MATERIALS (DEERFIELD BEACH, FLA.) 2021; 33:e2008528. [PMID: 33988861 DOI: 10.1002/adma.202008528] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 12/17/2020] [Revised: 03/17/2021] [Indexed: 06/12/2023]
Abstract
Correlated topological phases (CTPs) with interplay between topology and electronic correlations have attracted tremendous interest in condensed matter physics. Therein, correlated Weyl semimetals (WSMs) are rare in nature and, thus, have so far been less investigated experimentally. In particular, the experimental realization of the interacting WSM state with logarithmic Fermi velocity renormalization has not been achieved yet. Here, experimental evidence of a correlated magnetic WSM state with logarithmic renormalization in strained pyrochlore iridate Pr2 Ir2 O7 (PIO) which is a paramagnetic Luttinger semimetal in bulk, is reported. Benefitting from epitaxial strain, "bulk-absent" all-in-all-out antiferromagnetic ordering can be stabilized in PIO film, which breaks time-reversal symmetry and leads to a magnetic WSM state. With further analysis of the experimental data and renormalization group calculations, an interacting Weyl liquid state with logarithmically renormalized Fermi velocity, similar to that in graphene, is found, dressed by long-range Coulomb interactions. This work highlights the interplay of strain, magnetism, and topology with electronic correlations, and paves the way for strain-engineering of CTPs in pyrochlore iridates.
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Affiliation(s)
- Yangyang Li
- Center for Correlated Electron Systems, Institute for Basic Science (IBS), Seoul, 08826, Republic of Korea
- Department of Physics and Astronomy, Seoul National University, Seoul, 08826, Republic of Korea
| | - Taekoo Oh
- Center for Correlated Electron Systems, Institute for Basic Science (IBS), Seoul, 08826, Republic of Korea
- Department of Physics and Astronomy, Seoul National University, Seoul, 08826, Republic of Korea
- Center for Theoretical Physics (CTP), Seoul National University, Seoul, 08826, Republic of Korea
| | - Jaeseok Son
- Center for Correlated Electron Systems, Institute for Basic Science (IBS), Seoul, 08826, Republic of Korea
- Department of Physics and Astronomy, Seoul National University, Seoul, 08826, Republic of Korea
| | - Jeongkeun Song
- Center for Correlated Electron Systems, Institute for Basic Science (IBS), Seoul, 08826, Republic of Korea
- Department of Physics and Astronomy, Seoul National University, Seoul, 08826, Republic of Korea
| | - Mi Kyung Kim
- Center for Correlated Electron Systems, Institute for Basic Science (IBS), Seoul, 08826, Republic of Korea
- Department of Physics and Astronomy, Seoul National University, Seoul, 08826, Republic of Korea
| | - Dongjun Song
- Center for Correlated Electron Systems, Institute for Basic Science (IBS), Seoul, 08826, Republic of Korea
- Department of Physics and Astronomy, Seoul National University, Seoul, 08826, Republic of Korea
| | - Sukhyun Kim
- Center for Correlated Electron Systems, Institute for Basic Science (IBS), Seoul, 08826, Republic of Korea
- Department of Physics and Astronomy, Seoul National University, Seoul, 08826, Republic of Korea
| | - Seo Hyoung Chang
- Department of Physics, Chung-Ang University, Seoul, 156-756, Republic of Korea
| | - Changyoung Kim
- Center for Correlated Electron Systems, Institute for Basic Science (IBS), Seoul, 08826, Republic of Korea
- Department of Physics and Astronomy, Seoul National University, Seoul, 08826, Republic of Korea
| | - Bohm-Jung Yang
- Center for Correlated Electron Systems, Institute for Basic Science (IBS), Seoul, 08826, Republic of Korea
- Department of Physics and Astronomy, Seoul National University, Seoul, 08826, Republic of Korea
- Center for Theoretical Physics (CTP), Seoul National University, Seoul, 08826, Republic of Korea
| | - Tae Won Noh
- Center for Correlated Electron Systems, Institute for Basic Science (IBS), Seoul, 08826, Republic of Korea
- Department of Physics and Astronomy, Seoul National University, Seoul, 08826, Republic of Korea
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184
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Ou M, Wang X, Yu L, Liu C, Tao W, Ji X, Mei L. The Emergence and Evolution of Borophene. ADVANCED SCIENCE (WEINHEIM, BADEN-WURTTEMBERG, GERMANY) 2021; 8:2001801. [PMID: 34194924 PMCID: PMC8224432 DOI: 10.1002/advs.202001801] [Citation(s) in RCA: 39] [Impact Index Per Article: 13.0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/15/2020] [Revised: 09/19/2020] [Indexed: 05/14/2023]
Abstract
Neighboring carbon and sandwiched between non-metals and metals in the periodic table of the elements, boron is one of the most chemically and physically versatile elements, and can be manipulated to form dimensionally low planar structures (borophene) with intriguing properties. Herein, the theoretical research and experimental developments in the synthesis of borophene, as well as its excellent properties and application in many fields, are reviewed. The decade-long effort toward understanding the size-dependent structures of boron clusters and the theory-directed synthesis of borophene, including bottom-up approaches based on different foundations, as well as up-down approaches with different exfoliation modes, and the key factors influencing the synthetic effects, are comprehensively summarized. Owing to its excellent chemical, electronic, mechanical, and thermal properties, borophene has shown great promise in supercapacitor, battery, hydrogen-storage, and biomedical applications. Furthermore, borophene nanoplatforms used in various biomedical applications, such as bioimaging, drug delivery, and photonic therapy, are highlighted. Finally, research progress, challenges, and perspectives for the future development of borophene in large-scale production and other prospective applications are discussed.
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Affiliation(s)
- Meitong Ou
- School of Pharmaceutical Sciences (Shenzhen)Sun Yat‐sen UniversityGuangzhou510275P. R. China
| | - Xuan Wang
- School of Pharmaceutical Sciences (Shenzhen)Sun Yat‐sen UniversityGuangzhou510275P. R. China
| | - Liu Yu
- School of Pharmaceutical Sciences (Shenzhen)Sun Yat‐sen UniversityGuangzhou510275P. R. China
| | - Chuang Liu
- Center for Nanomedicine and Department of AnesthesiologyBrigham and Women's HospitalHarvard Medical SchoolBostonMA02115USA
| | - Wei Tao
- Center for Nanomedicine and Department of AnesthesiologyBrigham and Women's HospitalHarvard Medical SchoolBostonMA02115USA
| | - Xiaoyuan Ji
- School of Pharmaceutical Sciences (Shenzhen)Sun Yat‐sen UniversityGuangzhou510275P. R. China
- Academy of Medical Engineering and Translational MedicineTianjin UniversityTianjin300072China
| | - Lin Mei
- School of Pharmaceutical Sciences (Shenzhen)Sun Yat‐sen UniversityGuangzhou510275P. R. China
- Institute of Biomedical EngineeringChinese Academy of Medical Sciences and Peking Union Medical CollegeTianjin300192China
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185
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Xie YM, Gao XJ, Xu XY, Zhang CP, Hu JX, Gao JZ, Law KT. Kramers nodal line metals. Nat Commun 2021; 12:3064. [PMID: 34031382 PMCID: PMC8144424 DOI: 10.1038/s41467-021-22903-9] [Citation(s) in RCA: 6] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/04/2020] [Accepted: 04/06/2021] [Indexed: 11/09/2022] Open
Abstract
Recently, it was pointed out that all chiral crystals with spin-orbit coupling (SOC) can be Kramers Weyl semimetals (KWSs) which possess Weyl points pinned at time-reversal invariant momenta. In this work, we show that all achiral non-centrosymmetric materials with SOC can be a new class of topological materials, which we term Kramers nodal line metals (KNLMs). In KNLMs, there are doubly degenerate lines, which we call Kramers nodal lines (KNLs), connecting time-reversal invariant momenta. The KNLs create two types of Fermi surfaces, namely, the spindle torus type and the octdong type. Interestingly, all the electrons on octdong Fermi surfaces are described by two-dimensional massless Dirac Hamiltonians. These materials support quantized optical conductance in thin films. We further show that KNLMs can be regarded as parent states of KWSs. Therefore, we conclude that all non-centrosymmetric metals with SOC are topological, as they can be either KWSs or KNLMs.
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Affiliation(s)
- Ying-Ming Xie
- Department of Physics, Hong Kong University of Science and Technology, Hong Kong, China
| | - Xue-Jian Gao
- Department of Physics, Hong Kong University of Science and Technology, Hong Kong, China
| | - Xiao Yan Xu
- Department of Physics, University of California at San Diego, La Jolla, CA, USA
| | - Cheng-Ping Zhang
- Department of Physics, Hong Kong University of Science and Technology, Hong Kong, China
| | - Jin-Xin Hu
- Department of Physics, Hong Kong University of Science and Technology, Hong Kong, China
| | - Jason Z Gao
- Department of Physics, Hong Kong University of Science and Technology, Hong Kong, China
| | - K T Law
- Department of Physics, Hong Kong University of Science and Technology, Hong Kong, China.
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186
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Krempaský J, Nicolaï L, Gmitra M, Chen H, Fanciulli M, Guedes EB, Caputo M, Radović M, Volobuev VV, Caha O, Springholz G, Minár J, Dil JH. Triple-Point Fermions in Ferroelectric GeTe. PHYSICAL REVIEW LETTERS 2021; 126:206403. [PMID: 34110214 DOI: 10.1103/physrevlett.126.206403] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 11/13/2020] [Revised: 02/16/2021] [Accepted: 04/08/2021] [Indexed: 06/12/2023]
Abstract
Ferroelectric α-GeTe is unveiled to exhibit an intriguing multiple nontrivial topology of the electronic band structure due to the existence of triple-point and type-II Weyl fermions, which goes well beyond the giant Rashba spin splitting controlled by external fields as previously reported. Using spin- and angle-resolved photoemission spectroscopy combined with ab initio density functional theory, the unique spin texture around the triple point caused by the crossing of one spin-degenerate and two spin-split bands along the ferroelectric crystal axis is derived. This consistently reveals spin winding numbers that are coupled with time-reversal symmetry and Lorentz invariance, which are found to be equal for both triple-point pairs in the Brillouin zone. The rich manifold of effects opens up promising perspectives for studying nontrivial phenomena and multicomponent fermions in condensed matter systems.
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Affiliation(s)
- Juraj Krempaský
- Photon Science Division, Paul Scherrer Institut, CH-5232 Villigen, Switzerland
| | - Laurent Nicolaï
- New Technologies-Research Center, University of West Bohemia, 301 00 Plzeň 3, Czech Republic
| | - Martin Gmitra
- Institute of Physics, P. J. Šafárik University in Košice, Park Angelinum 9, 040 01 Košice, Slovakia
| | - Houke Chen
- Department of Physics, Tsinghua University, Beijing 100084, China
| | - Mauro Fanciulli
- Laboratoire de Physique des Matériaux et Surfaces, CY Cergy Paris Université, 95031 Cergy-Pontoise, France
| | - Eduardo B Guedes
- Photon Science Division, Paul Scherrer Institut, CH-5232 Villigen, Switzerland
| | - Marco Caputo
- Photon Science Division, Paul Scherrer Institut, CH-5232 Villigen, Switzerland
| | - Milan Radović
- Photon Science Division, Paul Scherrer Institut, CH-5232 Villigen, Switzerland
| | - Valentine V Volobuev
- International Research Centre MagTop, Institute of Physics, Polish Academy of Sciences, Aleja Lotnikow 32/46, PL-02668 Warsaw, Poland
- National Technical University "KhPI", Kyrpychova Street 2, 61002 Kharkiv, Ukraine
| | - Ondřej Caha
- Department of Condensed Matter Physics, Masaryk University, Kotlářská 267/2, 61137 Brno, Czech Republic
| | - Gunther Springholz
- Institut für Halbleiter-und Festkörperphysik, Johannes Kepler Universität, A-4040 Linz, Austria
| | - Jan Minár
- New Technologies-Research Center, University of West Bohemia, 301 00 Plzeň 3, Czech Republic
| | - J Hugo Dil
- Photon Science Division, Paul Scherrer Institut, CH-5232 Villigen, Switzerland
- Institut de Physique, École Polytechnique Fédérale de Lausanne, CH-1015 Lausanne, Switzerland
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187
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Topologically Protected Wormholes in Type-III Weyl Semimetal Co3In2X2 (X = S, Se). CONDENSED MATTER 2021. [DOI: 10.3390/condmat6020018] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/17/2022]
Abstract
The observation of wormholes has proven to be difficult in the field of astrophysics. However, with the discovery of novel topological quantum materials, it is possible to observe astrophysical and particle physics effects in condensed matter physics. It is proposed in this work that wormholes can exist in a type-III Weyl phase. In addition, these wormholes are topologically protected, making them feasible to create and measure in condensed matter systems. Finally, Co3In2X2 (X = S, Se) are identified as ideal type-III Weyl semimetals and experiments are put forward to confirm the existence of a type-III Weyl phase.
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188
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Dai J, Frantzeskakis E, Aryal N, Chen KW, Fortuna F, Rault JE, Le Fèvre P, Balicas L, Miyamoto K, Okuda T, Manousakis E, Baumbach RE, Santander-Syro AF. Experimental Observation and Spin Texture of Dirac Node Arcs in Tetradymite Topological Metals. PHYSICAL REVIEW LETTERS 2021; 126:196407. [PMID: 34047592 DOI: 10.1103/physrevlett.126.196407] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 11/15/2020] [Revised: 03/08/2021] [Accepted: 04/15/2021] [Indexed: 06/12/2023]
Abstract
We report the observation of a nontrivial spin texture in Dirac node arcs, i.e., novel topological objects formed when Dirac cones of massless particles extend along an open one-dimensional line in momentum space. We find that such states are present in all the compounds of the tetradymite M_{2}Te_{2}X family (M=Ti, Zr, or Hf and X=P or As) regardless of the weak or strong character of the topological invariant. The Dirac node arcs in tetradymites are thus the simplest possible textbook example of a type-I Dirac system with a single spin-polarized node arc.
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Affiliation(s)
- J Dai
- Université Paris-Saclay, CNRS, Institut des Sciences Moléculaires d'Orsay, 91405 Orsay, France
| | - E Frantzeskakis
- Université Paris-Saclay, CNRS, Institut des Sciences Moléculaires d'Orsay, 91405 Orsay, France
| | - N Aryal
- National High Magnetic Field Laboratory, Florida State University, Tallahassee, Florida 32306, USA
- Department of Physics, Florida State University, Tallahassee, Florida 32306, USA
| | - K-W Chen
- National High Magnetic Field Laboratory, Florida State University, Tallahassee, Florida 32306, USA
- Department of Physics, Florida State University, Tallahassee, Florida 32306, USA
| | - F Fortuna
- Université Paris-Saclay, CNRS, Institut des Sciences Moléculaires d'Orsay, 91405 Orsay, France
| | - J E Rault
- Synchrotron SOLEIL, L'Orme des Merisiers, Saint-Aubin-BP48, 91192 Gif-sur-Yvette, France
| | - P Le Fèvre
- Synchrotron SOLEIL, L'Orme des Merisiers, Saint-Aubin-BP48, 91192 Gif-sur-Yvette, France
| | - L Balicas
- National High Magnetic Field Laboratory, Florida State University, Tallahassee, Florida 32306, USA
- Department of Physics, Florida State University, Tallahassee, Florida 32306, USA
| | - K Miyamoto
- National High Magnetic Field Laboratory, Florida State University, Tallahassee, Florida 32306, USA
- Department of Physics, Florida State University, Tallahassee, Florida 32306, USA
| | - T Okuda
- Hiroshima Synchrotron Radiation Center (HSRC), Hiroshima University, 2-313 Kagamiyama, Higashi-Hiroshima 739-0046, Japan
| | - E Manousakis
- National High Magnetic Field Laboratory, Florida State University, Tallahassee, Florida 32306, USA
- Department of Physics, Florida State University, Tallahassee, Florida 32306, USA
- Department of Physics, National and Kapodistrian University of Athens, Panepistimioupolis, Zografos, 157 84 Athens, Greece
| | - R E Baumbach
- National High Magnetic Field Laboratory, Florida State University, Tallahassee, Florida 32306, USA
- Department of Physics, Florida State University, Tallahassee, Florida 32306, USA
| | - A F Santander-Syro
- Université Paris-Saclay, CNRS, Institut des Sciences Moléculaires d'Orsay, 91405 Orsay, France
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189
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Kalha C, Fernando NK, Bhatt P, Johansson FOL, Lindblad A, Rensmo H, Medina LZ, Lindblad R, Siol S, Jeurgens LPH, Cancellieri C, Rossnagel K, Medjanik K, Schönhense G, Simon M, Gray AX, Nemšák S, Lömker P, Schlueter C, Regoutz A. Hard x-ray photoelectron spectroscopy: a snapshot of the state-of-the-art in 2020. JOURNAL OF PHYSICS. CONDENSED MATTER : AN INSTITUTE OF PHYSICS JOURNAL 2021; 33:233001. [PMID: 33647896 DOI: 10.1088/1361-648x/abeacd] [Citation(s) in RCA: 21] [Impact Index Per Article: 7.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 12/21/2020] [Accepted: 03/01/2021] [Indexed: 06/12/2023]
Abstract
Hard x-ray photoelectron spectroscopy (HAXPES) is establishing itself as an essential technique for the characterisation of materials. The number of specialised photoelectron spectroscopy techniques making use of hard x-rays is steadily increasing and ever more complex experimental designs enable truly transformative insights into the chemical, electronic, magnetic, and structural nature of materials. This paper begins with a short historic perspective of HAXPES and spans from developments in the early days of photoelectron spectroscopy to provide an understanding of the origin and initial development of the technique to state-of-the-art instrumentation and experimental capabilities. The main motivation for and focus of this paper is to provide a picture of the technique in 2020, including a detailed overview of available experimental systems worldwide and insights into a range of specific measurement modi and approaches. We also aim to provide a glimpse into the future of the technique including possible developments and opportunities.
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Affiliation(s)
- Curran Kalha
- Department of Chemistry, University College London, 20 Gordon Street, London, WC1H 0AJ, United Kingdom
| | - Nathalie K Fernando
- Department of Chemistry, University College London, 20 Gordon Street, London, WC1H 0AJ, United Kingdom
| | - Prajna Bhatt
- Department of Chemistry, University College London, 20 Gordon Street, London, WC1H 0AJ, United Kingdom
| | - Fredrik O L Johansson
- Department of Physics and Astronomy, Uppsala University, Box 516, 75120 Uppsala, Sweden
| | - Andreas Lindblad
- Department of Physics and Astronomy, Uppsala University, Box 516, 75120 Uppsala, Sweden
| | - Håkan Rensmo
- Department of Physics and Astronomy, Uppsala University, Box 516, 75120 Uppsala, Sweden
| | - León Zendejas Medina
- Department of Chemistry-Ångström Laboratory, Uppsala University, Box 538, SE-75121, Uppsala, Sweden
| | - Rebecka Lindblad
- Department of Chemistry-Ångström Laboratory, Uppsala University, Box 538, SE-75121, Uppsala, Sweden
| | - Sebastian Siol
- Empa, Swiss Federal Laboratories for Materials Science and Technology, Laboratory for Joining Technologies and Corrosion, Dübendorf, Switzerland
| | - Lars P H Jeurgens
- Empa, Swiss Federal Laboratories for Materials Science and Technology, Laboratory for Joining Technologies and Corrosion, Dübendorf, Switzerland
| | - Claudia Cancellieri
- Empa, Swiss Federal Laboratories for Materials Science and Technology, Laboratory for Joining Technologies and Corrosion, Dübendorf, Switzerland
| | - Kai Rossnagel
- Institute of Experimental and Applied Physics, Kiel University, 24098 Kiel, Germany
- Ruprecht Haensel Laboratory, Deutsches Elektronen-Synchrotron DESY, 22607 Hamburg, Germany
| | - Katerina Medjanik
- Johannes Gutenberg Universität, Institut für Physik, 55128 Mainz, Germany
| | - Gerd Schönhense
- Johannes Gutenberg Universität, Institut für Physik, 55128 Mainz, Germany
| | - Marc Simon
- Sorbonne Université, CNRS, Laboratoire de Chimie Physique-Matière et Rayonnement, LCPMR, F-75005 Paris, France
| | - Alexander X Gray
- Department of Physics, Temple University, Philadelphia, PA 19122, United States of America
| | - Slavomír Nemšák
- Advanced Light Source, Lawrence Berkeley National Laboratory, Berkeley, CA 94720, United States of America
| | - Patrick Lömker
- Deutsches Elektronen-Synchrotron DESY, 22607 Hamburg, Germany
| | | | - Anna Regoutz
- Department of Chemistry, University College London, 20 Gordon Street, London, WC1H 0AJ, United Kingdom
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190
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Rylands C, Parhizkar A, Burkov AA, Galitski V. Chiral Anomaly in Interacting Condensed Matter Systems. PHYSICAL REVIEW LETTERS 2021; 126:185303. [PMID: 34018774 DOI: 10.1103/physrevlett.126.185303] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 02/15/2021] [Accepted: 04/09/2021] [Indexed: 06/12/2023]
Abstract
The chiral anomaly is a fundamental quantum mechanical phenomenon which is of great importance to both particle physics and condensed matter physics alike. In the context of QED, it manifests as the breaking of chiral symmetry in the presence of electromagnetic fields. It is also known that anomalous chiral symmetry breaking can occur through interactions alone, as is the case for interacting one-dimensional systems. In this Letter, we investigate the interplay between these two modes of anomalous chiral symmetry breaking in the context of interacting Weyl semimetals. Using Fujikawa's path integral method, we show that the chiral charge continuity equation is modified by the presence of interactions which can be viewed as including the effect of the electric and magnetic fields generated by the interacting quantum matter. This can be understood further using dimensional reduction and a Luttinger liquid description of the lowest Landau level. These effects manifest themselves in the nonlinear response of the system. In particular, we find an interaction-dependent density response due to a change in the magnetic field as well as a contribution to the nonequilibrium and inhomogeneous anomalous Hall response while preserving its equilibrium value.
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Affiliation(s)
- Colin Rylands
- Joint Quantum Institute and Condensed Matter Theory Center, University of Maryland, College Park, Maryland 20742, USA
| | - Alireza Parhizkar
- Joint Quantum Institute and Condensed Matter Theory Center, University of Maryland, College Park, Maryland 20742, USA
| | - Anton A Burkov
- Department of Physics and Astronomy, University of Waterloo, Waterloo, Ontario N2L 3G1, Canada
- Perimeter Institute for Theoretical Physics, Waterloo, Ontario N2L 2Y5, Canada
| | - Victor Galitski
- Joint Quantum Institute and Condensed Matter Theory Center, University of Maryland, College Park, Maryland 20742, USA
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191
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Mohajerani A, Faraei Z, Jafari SA. Fast nuclear spin relaxation rates in tilted cone Weyl semimetals: redshift factors from Korringa relation. JOURNAL OF PHYSICS. CONDENSED MATTER : AN INSTITUTE OF PHYSICS JOURNAL 2021; 33:215603. [PMID: 33588403 DOI: 10.1088/1361-648x/abe64e] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 11/03/2020] [Accepted: 02/15/2021] [Indexed: 06/12/2023]
Abstract
Spin lattice relaxation rate is investigated for 3D tilted cone Weyl semimetals (TCWSMs). The nuclear spin relaxation rate is presented as a function of temperature and tilt parameter. We find that the relaxation rate behaves as(1-ζ2)-αwithα≈ 9 where 0 ⩽ζ< 1 is the tilt parameter. We demonstrate that such a strong enhancement forζ≲ 1 that gives rise to very fast relaxation rates, is contributed by a new hyperfine interactions arising from the tilt itself. This can be attributed to the combination of anisotropy of the Fermi surface and an additional part related to the structure of the spacetime: extracting an effective density of states (DOS)ρ̃from the Korringa relation, we show that it is related to the DOSρof the tilted cone dispersion by the 'redshift factor' asρ̃=ρ/1-ζ2. We interpret this relation as NMR manifestation of an emergent underlying spacetime structure in TCWSMs.
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Affiliation(s)
- A Mohajerani
- Department of Basic Sciences, Tarbiat Modares University (TMU), Tehran 14115-175, Iran
| | - Z Faraei
- Department of Physics, Sharif University of Technology, Tehran 11155-9161, Iran
| | - S A Jafari
- Department of Physics, Sharif University of Technology, Tehran 11155-9161, Iran
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192
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Bedoya-Pinto A, Liu D, Tan H, Pandeya AK, Chang K, Zhang J, Parkin SSP. Large Fermi-Energy Shift and Suppression of Trivial Surface States in NbP Weyl Semimetal Thin Films. ADVANCED MATERIALS (DEERFIELD BEACH, FLA.) 2021; 33:e2008634. [PMID: 33942944 DOI: 10.1002/adma.202008634] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 12/22/2020] [Revised: 02/21/2021] [Indexed: 06/12/2023]
Abstract
Weyl semimetals, a class of 3D topological materials, exhibit a unique electronic structure featuring linear band crossings and disjoint surface states (Fermi-arcs). While first demonstrations of topologically driven phenomena have been realized in bulk crystals, efficient routes to control the electronic structure have remained largely unexplored. Here, a dramatic modification of the electronic structure in epitaxially grown NbP Weyl semimetal thin films is reported, using in situ surface engineering and chemical doping strategies that do not alter the NbP lattice structure and symmetry, retaining its topological nature. Through the preparation of a dangling-bond-free, P-terminated surface which manifests in a surface reconstruction, all the well-known trivial surface states of NbP are fully suppressed, resulting in a purely topological Fermi-arc dispersion. In addition, a substantial Fermi-energy shift from -0.2 to 0.3 eV across the Weyl points is achieved by surface chemical doping, unlocking access to the hitherto unexplored n-type region of the Weyl spectrum. These findings constitute a milestone toward surface-state and Fermi-level engineering of topological bands in Weyl semimetals, and, while there are still challenges in minimizing doping-driven disorder and grain boundary density in the films, they do represent a major advance to realize device heterostructures based on Weyl physics.
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Affiliation(s)
- Amilcar Bedoya-Pinto
- Max Planck-Institute of Microstructure Physics, Weinberg 2, Halle (Saale), 06120, Germany
| | - Defa Liu
- Max Planck-Institute of Microstructure Physics, Weinberg 2, Halle (Saale), 06120, Germany
| | - Hengxin Tan
- Max Planck-Institute of Microstructure Physics, Weinberg 2, Halle (Saale), 06120, Germany
| | | | - Kai Chang
- Max Planck-Institute of Microstructure Physics, Weinberg 2, Halle (Saale), 06120, Germany
| | - Jibo Zhang
- Max Planck-Institute of Microstructure Physics, Weinberg 2, Halle (Saale), 06120, Germany
| | - Stuart S P Parkin
- Max Planck-Institute of Microstructure Physics, Weinberg 2, Halle (Saale), 06120, Germany
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193
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Pal D, Kumar S, Shahi P, Dan S, Verma A, Gangwar VK, Singh M, Chakravarty S, Uwatoko Y, Saha S, Patil S, Chatterjee S. Defect induced ferromagnetic ordering and room temperature negative magnetoresistance in MoTeP. Sci Rep 2021; 11:9104. [PMID: 33907273 PMCID: PMC8079386 DOI: 10.1038/s41598-021-88669-8] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/27/2020] [Accepted: 03/03/2021] [Indexed: 02/02/2023] Open
Abstract
The magneto-transport, magnetization and theoretical electronic-structure have been investigated on type-II Weyl semimetallic MoTeP. The ferromagnetic ordering is observed in the studied sample and it has been shown that the observed magnetic ordering is due to the defect states. It has also been demonstrated that the presence of ferromagnetic ordering in effect suppresses the magnetoresistance (MR) significantly. Interestingly, a change-over from positive to negative MR is observed at higher temperature which has been attributed to the dominance of spin scattering suppression.
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Affiliation(s)
- Debarati Pal
- Department of Physics, Indian Institute of Technology (Banaras Hindu University), Varanasi, 221005, India
| | - Shiv Kumar
- Hiroshima Synchrotron Radiation Center, Hiroshima University, Higashi-Hiroshima City, 739-0046, Japan
| | - Prashant Shahi
- Department of Physics, D.D.U. Gorakhpur University, Gorakhpur, 273009, India
| | - Sambhab Dan
- Department of Physics, Indian Institute of Technology (Banaras Hindu University), Varanasi, 221005, India
| | - Abhineet Verma
- Department of Chemistry, Institute of Science (Banaras Hindu University), Varanasi, 221005, India
| | - Vinod K Gangwar
- Department of Physics, Indian Institute of Technology (Banaras Hindu University), Varanasi, 221005, India
| | - Mahima Singh
- Department of Physics, Indian Institute of Technology (Banaras Hindu University), Varanasi, 221005, India
| | - Sujoy Chakravarty
- UGC-DAE Consortium for Scientific Research, Kalpakkam Node, Kokilamedu, 603104, India
| | - Yoshiya Uwatoko
- Institute for Solid State Physics, University of Tokyo, Kashiwa, Chiba, 277-8581, Japan
| | - Satyen Saha
- Department of Chemistry, Institute of Science (Banaras Hindu University), Varanasi, 221005, India
| | - Swapnil Patil
- Department of Physics, Indian Institute of Technology (Banaras Hindu University), Varanasi, 221005, India.
| | - Sandip Chatterjee
- Department of Physics, Indian Institute of Technology (Banaras Hindu University), Varanasi, 221005, India.
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194
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Ma HY, Guan D, Wang S, Li Y, Liu C, Zheng H, Jia JF. Quantum spin Hall and quantum anomalous Hall states in magnetic Ti 2Te 2O single layer. JOURNAL OF PHYSICS. CONDENSED MATTER : AN INSTITUTE OF PHYSICS JOURNAL 2021; 33:21LT01. [PMID: 33588390 DOI: 10.1088/1361-648x/abe647] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 10/27/2020] [Accepted: 02/15/2021] [Indexed: 06/12/2023]
Abstract
Magnetic topological insulators, such as MnBi2Te4have attracted great attention recently due to their application to the quantum anomalous Hall (QAH) effect. However, the magnetic quantum spin Hall (QSH) effect in two-dimensional (2D) materials has not yet been reported. Here based on first-principle calculations we find that Ti2Te2O, a van der Waals layered compound, can cherish both the QAH and QSH states, depending on the magnetic order in its single layer. If the single layer was in a chessboard antiferromagnetic (FM) state, it is a QSH insulator which carries two counterpropagating helical edge states. The spin-orbit-couplings induced bulk band gap can approach as large as 0.31 eV. On the other hand, if the monolayer becomes FM, exchange interactions would push one pair of bands away from the Fermi energy and leave only one chiral edge state remaining, which turns the compound into a Chern insulator (precisely, it is semimetallic with a topologically direct band gap). Both magnetic orders explicitly break the time reversal symmetry and split the energy bands of different spin orientations. To our knowledge, Ti2Te2O is the first compound that predicted to possess both intrinsic QSH and QAH effects. Our works provide new possibilities to reach a controllable phase transition between two topological nontrivial phases through magnetism tailoring.
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Affiliation(s)
- Hai-Yang Ma
- Key Laboratory of Artificial Structures and Quantum Control (Ministry of Education), Shenyang National Laboratory for Materials Science, School of Physics and Astronomy, Shanghai Jiao Tong University, Shanghai 200240, People's Republic of China
| | - Dandan Guan
- Key Laboratory of Artificial Structures and Quantum Control (Ministry of Education), Shenyang National Laboratory for Materials Science, School of Physics and Astronomy, Shanghai Jiao Tong University, Shanghai 200240, People's Republic of China
- Tsung-Dao Lee Institute, Shanghai 200240, People's Republic of China
| | - Shiyong Wang
- Key Laboratory of Artificial Structures and Quantum Control (Ministry of Education), Shenyang National Laboratory for Materials Science, School of Physics and Astronomy, Shanghai Jiao Tong University, Shanghai 200240, People's Republic of China
- Tsung-Dao Lee Institute, Shanghai 200240, People's Republic of China
| | - Yaoyi Li
- Key Laboratory of Artificial Structures and Quantum Control (Ministry of Education), Shenyang National Laboratory for Materials Science, School of Physics and Astronomy, Shanghai Jiao Tong University, Shanghai 200240, People's Republic of China
- Tsung-Dao Lee Institute, Shanghai 200240, People's Republic of China
| | - Canhua Liu
- Key Laboratory of Artificial Structures and Quantum Control (Ministry of Education), Shenyang National Laboratory for Materials Science, School of Physics and Astronomy, Shanghai Jiao Tong University, Shanghai 200240, People's Republic of China
- Tsung-Dao Lee Institute, Shanghai 200240, People's Republic of China
| | - Hao Zheng
- Key Laboratory of Artificial Structures and Quantum Control (Ministry of Education), Shenyang National Laboratory for Materials Science, School of Physics and Astronomy, Shanghai Jiao Tong University, Shanghai 200240, People's Republic of China
- Tsung-Dao Lee Institute, Shanghai 200240, People's Republic of China
| | - Jin-Feng Jia
- Key Laboratory of Artificial Structures and Quantum Control (Ministry of Education), Shenyang National Laboratory for Materials Science, School of Physics and Astronomy, Shanghai Jiao Tong University, Shanghai 200240, People's Republic of China
- Tsung-Dao Lee Institute, Shanghai 200240, People's Republic of China
- CAS Center for Excellence in Topological Quantum Computation, University of Chinese Academy of Sciences, Beijing 100190, People's Republic of China
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195
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Shao J, Yan L. Longitudinal magnetoconductivity of tilted type-I Weyl semimetals from semiclassical to ultra-quantum regime. JOURNAL OF PHYSICS. CONDENSED MATTER : AN INSTITUTE OF PHYSICS JOURNAL 2021; 33:185704. [PMID: 33711830 DOI: 10.1088/1361-648x/abee3e] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 12/28/2020] [Accepted: 03/12/2021] [Indexed: 06/12/2023]
Abstract
Weyl semimetals (WSMs) display many unusual magnetotransport phenomena. Here, based on the Landau quantization and Boltzmann equation, we theoretically study the longitudinal magnetoconductivity for tilted type-I WSMs from weak to strong magnetic field within a unified framework. It is found that, in semiclassical (weak magnetic field) regime, the conductivity has an angular dependentB-linear term besides theB-quadratic term common to isotropic nodes. In ultra-quantum (strong magnetic field) regime, the magnetoconductivity shows a linear dependence onB, and this dependence is affected by the tilt. In the intermediate regime, magnetoconductivity shows a tilt-modified quantum oscillation behavior due to the oscillation in the density of state. These findings recover the results for isotropic nodes without tilt, and suggest a possible way to identify the tilt axis of tilted WSMs through magnetotransport experiment.
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Affiliation(s)
- Jianmei Shao
- College of Electronics & Information Engineering, Guangdong Ocean University, Zhanjiang 524088, Guangdong, People's Republic of China
| | - Lijuan Yan
- College of Electronics & Information Engineering, Guangdong Ocean University, Zhanjiang 524088, Guangdong, People's Republic of China
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196
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Li J, Sun Y, Wu M, Pan H. Novel electric field effects on magneto-optical conductivity in eight- Pmmnborophene. JOURNAL OF PHYSICS. CONDENSED MATTER : AN INSTITUTE OF PHYSICS JOURNAL 2021; 33:185501. [PMID: 33761494 DOI: 10.1088/1361-648x/abf19e] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 01/16/2021] [Accepted: 03/24/2021] [Indexed: 06/12/2023]
Abstract
We theoretically study the Landau levels and the magneto-optical conductivity of eight-Pmmnborophene in the presence of a perpendicular magnetic field and an inplane electric field. We find that in the absence of the inplane electric field, the magneto-optical conductivity of eight-Pmmnborophene presents a series of striking single resonance peaks as functions of the frequencyω, and the longitudinal conductivities are found to be anisotropic due to its anisotropic tilted Dirac cones. In the presence of the inplane electric field, some novel effects are predicted on the Landau levels and the magneto-optical conductivity. The Landau level spacings in the two tilted Dirac cones are different, which lifts the degeneracy of the twofold valley, and the magneto-optical conductivity appears a double peak structure. We also discuss the influence of the chemical potential between different Landau levels on the double peak of the magneto-optical response. The valley related magneto-optical properties in the anisotropic structure may make eight-Pmmnborophene a candidate for the new optical devices.
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Affiliation(s)
- Jing Li
- Department of Physics, Beihang University, Beijing 100191, People's Republic of China
| | - Yanmei Sun
- Department of Physics, Beihang University, Beijing 100191, People's Republic of China
| | - Meimei Wu
- Department of Physics, Beihang University, Beijing 100191, People's Republic of China
| | - Hui Pan
- Department of Physics, Beihang University, Beijing 100191, People's Republic of China
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197
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Gracia-Abad R, Sangiao S, Bigi C, Kumar Chaluvadi S, Orgiani P, De Teresa JM. Omnipresence of Weak Antilocalization (WAL) in Bi 2Se 3 Thin Films: A Review on Its Origin. NANOMATERIALS (BASEL, SWITZERLAND) 2021; 11:1077. [PMID: 33922019 PMCID: PMC8143463 DOI: 10.3390/nano11051077] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 03/29/2021] [Revised: 04/18/2021] [Accepted: 04/19/2021] [Indexed: 11/23/2022]
Abstract
Topological insulators are materials with time-reversal symmetric states of matter in which an insulating bulk is surrounded by protected Dirac-like edge or surface states. Among topological insulators, Bi2Se3 has attracted special attention due to its simple surface band structure and its relatively large band gap that should enhance the contribution of its surface to transport, which is usually masked by the appearance of defects. In order to avoid this difficulty, several features characteristic of topological insulators in the quantum regime, such as the weak-antilocalization effect, can be explored through magnetotransport experiments carried out on thin films of this material. Here, we review the existing literature on the magnetotransport properties of Bi2Se3 thin films, paying thorough attention to the weak-antilocalization effect, which is omnipresent no matter the film quality. We carefully follow the different situations found in reported experiments, from the most ideal situations, with a strong surface contribution, towards more realistic cases where the bulk contribution dominates. We have compared the transport data found in literature to shed light on the intrinsic properties of Bi2Se3, finding a clear relationship between the mobility and the phase coherence length of the films that could trigger further experiments on transport in topological systems.
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Affiliation(s)
- Rubén Gracia-Abad
- Departamento de Física de la Materia Condensada, Universidad de Zaragoza, 50009 Zaragoza, Spain;
- Laboratorio de Microscopías Avanzadas (LMA), Universidad de Zaragoza, 50018 Zaragoza, Spain
- Instituto de Nanociencia y Materiales de Aragón (INMA), CSIC-Universidad de Zaragoza, 50009 Zaragoza, Spain
| | - Soraya Sangiao
- Departamento de Física de la Materia Condensada, Universidad de Zaragoza, 50009 Zaragoza, Spain;
- Laboratorio de Microscopías Avanzadas (LMA), Universidad de Zaragoza, 50018 Zaragoza, Spain
- Instituto de Nanociencia y Materiales de Aragón (INMA), CSIC-Universidad de Zaragoza, 50009 Zaragoza, Spain
| | - Chiara Bigi
- CNR-IOM, TASC Laboratory in Area Science Park, 34139 Triestre, Italy; (C.B.); (S.K.C.); (P.O.)
| | - Sandeep Kumar Chaluvadi
- CNR-IOM, TASC Laboratory in Area Science Park, 34139 Triestre, Italy; (C.B.); (S.K.C.); (P.O.)
| | - Pasquale Orgiani
- CNR-IOM, TASC Laboratory in Area Science Park, 34139 Triestre, Italy; (C.B.); (S.K.C.); (P.O.)
| | - José María De Teresa
- Departamento de Física de la Materia Condensada, Universidad de Zaragoza, 50009 Zaragoza, Spain;
- Laboratorio de Microscopías Avanzadas (LMA), Universidad de Zaragoza, 50018 Zaragoza, Spain
- Instituto de Nanociencia y Materiales de Aragón (INMA), CSIC-Universidad de Zaragoza, 50009 Zaragoza, Spain
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198
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Wang ZY, Cheng XC, Wang BZ, Zhang JY, Lu YH, Yi CR, Niu S, Deng Y, Liu XJ, Chen S, Pan JW. Realization of an ideal Weyl semimetal band in a quantum gas with 3D spin-orbit coupling. Science 2021; 372:271-276. [PMID: 33859030 DOI: 10.1126/science.abc0105] [Citation(s) in RCA: 22] [Impact Index Per Article: 7.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/02/2020] [Accepted: 03/12/2021] [Indexed: 11/02/2022]
Abstract
Weyl semimetals are three-dimensional (3D) gapless topological phases with Weyl cones in the bulk band. According to lattice theory, Weyl cones must come in pairs, with the minimum number of cones being two. A semimetal with only two Weyl cones is an ideal Weyl semimetal (IWSM). Here we report the experimental realization of an IWSM band by engineering 3D spin-orbit coupling for ultracold atoms. The topological Weyl points are clearly measured via the virtual slicing imaging technique in equilibrium and are further resolved in the quench dynamics. The realization of an IWSM band opens an avenue to investigate various exotic phenomena that are difficult to access in solids.
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Affiliation(s)
- Zong-Yao Wang
- Hefei National Laboratory for Physical Sciences at the Microscale and Department of Modern Physics, University of Science and Technology of China, Hefei, Anhui 230026, China.,Shanghai Branch, CAS Center for Excellence in Quantum Information and Quantum Physics, University of Science and Technology of China, Shanghai 201315, China.,Shanghai Research Center for Quantum Science, Shanghai 201315, China
| | - Xiang-Can Cheng
- Hefei National Laboratory for Physical Sciences at the Microscale and Department of Modern Physics, University of Science and Technology of China, Hefei, Anhui 230026, China.,Shanghai Branch, CAS Center for Excellence in Quantum Information and Quantum Physics, University of Science and Technology of China, Shanghai 201315, China.,Shanghai Research Center for Quantum Science, Shanghai 201315, China
| | - Bao-Zong Wang
- Hefei National Laboratory for Physical Sciences at the Microscale and Department of Modern Physics, University of Science and Technology of China, Hefei, Anhui 230026, China.,International Center for Quantum Materials, School of Physics, Peking University, Beijing 100871, China
| | - Jin-Yi Zhang
- Hefei National Laboratory for Physical Sciences at the Microscale and Department of Modern Physics, University of Science and Technology of China, Hefei, Anhui 230026, China.,Shanghai Branch, CAS Center for Excellence in Quantum Information and Quantum Physics, University of Science and Technology of China, Shanghai 201315, China.,Shanghai Research Center for Quantum Science, Shanghai 201315, China
| | - Yue-Hui Lu
- International Center for Quantum Materials, School of Physics, Peking University, Beijing 100871, China.,CAS Center for Excellence in Topological Quantum Computation, University of Chinese Academy of Sciences, Beijing 100190, China
| | - Chang-Rui Yi
- Hefei National Laboratory for Physical Sciences at the Microscale and Department of Modern Physics, University of Science and Technology of China, Hefei, Anhui 230026, China.,Shanghai Branch, CAS Center for Excellence in Quantum Information and Quantum Physics, University of Science and Technology of China, Shanghai 201315, China.,Shanghai Research Center for Quantum Science, Shanghai 201315, China
| | - Sen Niu
- International Center for Quantum Materials, School of Physics, Peking University, Beijing 100871, China.,CAS Center for Excellence in Topological Quantum Computation, University of Chinese Academy of Sciences, Beijing 100190, China
| | - Youjin Deng
- Hefei National Laboratory for Physical Sciences at the Microscale and Department of Modern Physics, University of Science and Technology of China, Hefei, Anhui 230026, China.,Shanghai Branch, CAS Center for Excellence in Quantum Information and Quantum Physics, University of Science and Technology of China, Shanghai 201315, China.,Shanghai Research Center for Quantum Science, Shanghai 201315, China
| | - Xiong-Jun Liu
- International Center for Quantum Materials, School of Physics, Peking University, Beijing 100871, China. .,CAS Center for Excellence in Topological Quantum Computation, University of Chinese Academy of Sciences, Beijing 100190, China
| | - Shuai Chen
- Hefei National Laboratory for Physical Sciences at the Microscale and Department of Modern Physics, University of Science and Technology of China, Hefei, Anhui 230026, China. .,Shanghai Branch, CAS Center for Excellence in Quantum Information and Quantum Physics, University of Science and Technology of China, Shanghai 201315, China.,Shanghai Research Center for Quantum Science, Shanghai 201315, China
| | - Jian-Wei Pan
- Hefei National Laboratory for Physical Sciences at the Microscale and Department of Modern Physics, University of Science and Technology of China, Hefei, Anhui 230026, China. .,Shanghai Branch, CAS Center for Excellence in Quantum Information and Quantum Physics, University of Science and Technology of China, Shanghai 201315, China.,Shanghai Research Center for Quantum Science, Shanghai 201315, China
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199
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Goldman N, Yefsah T. The Weyl side of ultracold matter. Science 2021; 372:234-235. [PMID: 33859019 DOI: 10.1126/science.abg0892] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/02/2022]
Affiliation(s)
- Nathan Goldman
- Interdisciplinary Center for Nonlinear Phenomena and Complex Systems, Université Libre de Bruxelles, CP 231, Campus Plaine, B-1050 Brussels, Belgium
| | - Tarik Yefsah
- Laboratoire Kastler Brossel, ENS-Université PSL, CNRS, Sorbonne Université, Collège de France, 24 rue Lhomond 75005 Paris, France.
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200
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Beaulieu S, Dong S, Tancogne-Dejean N, Dendzik M, Pincelli T, Maklar J, Xian RP, Sentef MA, Wolf M, Rubio A, Rettig L, Ernstorfer R. Ultrafast dynamical Lifshitz transition. SCIENCE ADVANCES 2021; 7:7/17/eabd9275. [PMID: 33883128 PMCID: PMC8059938 DOI: 10.1126/sciadv.abd9275] [Citation(s) in RCA: 12] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 07/24/2020] [Accepted: 03/04/2021] [Indexed: 06/12/2023]
Abstract
Fermi surface is at the heart of our understanding of metals and strongly correlated many-body systems. An abrupt change in the Fermi surface topology, also called Lifshitz transition, can lead to the emergence of fascinating phenomena like colossal magnetoresistance and superconductivity. While Lifshitz transitions have been demonstrated for a broad range of materials by equilibrium tuning of macroscopic parameters such as strain, doping, pressure, and temperature, a nonequilibrium dynamical route toward ultrafast modification of the Fermi surface topology has not been experimentally demonstrated. Combining time-resolved multidimensional photoemission spectroscopy with state-of-the-art TDDFT+U simulations, we introduce a scheme for driving an ultrafast Lifshitz transition in the correlated type-II Weyl semimetal T d-MoTe2 We demonstrate that this nonequilibrium topological electronic transition finds its microscopic origin in the dynamical modification of the effective electronic correlations. These results shed light on a previously unexplored ultrafast scheme for controlling the Fermi surface topology in correlated quantum materials.
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Affiliation(s)
- Samuel Beaulieu
- Fritz Haber Institute of the Max Planck Society, Faradayweg 4-6, Berlin 14195, Germany.
| | - Shuo Dong
- Fritz Haber Institute of the Max Planck Society, Faradayweg 4-6, Berlin 14195, Germany
| | - Nicolas Tancogne-Dejean
- Max Planck Institute for the Structure and Dynamics of Matter, Luruper Chaussee 149, Hamburg 22761, Germany.
| | - Maciej Dendzik
- Fritz Haber Institute of the Max Planck Society, Faradayweg 4-6, Berlin 14195, Germany
- Department of Applied Physics, KTH Royal Institute of Technology, Hannes Alfvéns väg 12, 114 19 Stockholm, Sweden
| | - Tommaso Pincelli
- Fritz Haber Institute of the Max Planck Society, Faradayweg 4-6, Berlin 14195, Germany
| | - Julian Maklar
- Fritz Haber Institute of the Max Planck Society, Faradayweg 4-6, Berlin 14195, Germany
| | - R Patrick Xian
- Fritz Haber Institute of the Max Planck Society, Faradayweg 4-6, Berlin 14195, Germany
| | - Michael A Sentef
- Max Planck Institute for the Structure and Dynamics of Matter, Luruper Chaussee 149, Hamburg 22761, Germany
| | - Martin Wolf
- Fritz Haber Institute of the Max Planck Society, Faradayweg 4-6, Berlin 14195, Germany
| | - Angel Rubio
- Max Planck Institute for the Structure and Dynamics of Matter, Luruper Chaussee 149, Hamburg 22761, Germany
- Center for Computational Quantum Physics (CCQ), Flatiron Institute, 162 Fifth Avenue, New York, NY 10010, USA
| | - Laurenz Rettig
- Fritz Haber Institute of the Max Planck Society, Faradayweg 4-6, Berlin 14195, Germany
| | - Ralph Ernstorfer
- Fritz Haber Institute of the Max Planck Society, Faradayweg 4-6, Berlin 14195, Germany.
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