1
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Yu H, Heine T. Prediction of metal-free Stoner and Mott-Hubbard magnetism in triangulene-based two-dimensional polymers. SCIENCE ADVANCES 2024; 10:eadq7954. [PMID: 39356753 DOI: 10.1126/sciadv.adq7954] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/31/2024] [Accepted: 08/26/2024] [Indexed: 10/04/2024]
Abstract
Ferromagnetism and antiferromagnetism require robust long-range magnetic ordering, which typically involves strongly interacting spins localized at transition metal atoms. However, in metal-free systems, the spin orbitals are largely delocalized, and weak coupling between the spins in the lattice hampers long-range ordering. Metal-free magnetism is of fundamental interest to physical sciences, unlocking unprecedented dimensions for strongly correlated materials and biocompatible magnets. Here, we present a strategy to achieve strong coupling between spin centers of planar radical monomers in π-conjugated two-dimensional (2D) polymers and rationally control the orderings. If the π-states in these triangulene-based 2D polymers are half-occupied, then we predict that they are antiferromagnetic Mott-Hubbard insulators. Incorporating a boron or nitrogen heteroatom per monomer results in Stoner ferromagnetism and half-metallicity, with the Fermi level located at spin-polarized Dirac points. An unprecedented antiferromagnetic half-semiconductor is observed in a binary boron-nitrogen-centered 2D polymer. Our findings pioneer Stoner and Mott-Hubbard magnetism emerging in the electronic π-system of crystalline-conjugated 2D polymers.
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Affiliation(s)
- Hongde Yu
- Faculty of Chemistry and Food Chemistry, TU Dresden, Bergstrasse 66c, 01069 Dresden, Germany
| | - Thomas Heine
- Faculty of Chemistry and Food Chemistry, TU Dresden, Bergstrasse 66c, 01069 Dresden, Germany
- Helmholtz-Zentrum Dresden-Rossendorf, Centrum for Advanced Systems Understanding, CASUS, Untermarkt 20, 02826 Görlitz, Germany
- Department of Chemistry, Yonsei University and IBS Center for Nanomedicine, Seodaemun-gu, Seoul 120-749, Republic of Korea
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2
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Wu W, Sun S, Tang CS, Wu J, Ma Y, Zhang L, Cai C, Zhong J, Milošević MV, Wee ATS, Yin X. Realization of a 2D Lieb Lattice in a Metal-Inorganic Framework with Partial Flat Bands and Topological Edge States. ADVANCED MATERIALS (DEERFIELD BEACH, FLA.) 2024; 36:e2405615. [PMID: 39180271 DOI: 10.1002/adma.202405615] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 04/19/2024] [Revised: 08/05/2024] [Indexed: 08/26/2024]
Abstract
Flat bands and Dirac cones in materials are the source of the exotic electronic and topological properties. The Lieb lattice is expected to host these electronic structures, arising from quantum destructive interference. Nevertheless, the experimental realization of a 2D Lieb lattice remained challenging to date due to its intrinsic structural instability. After computationally designing a Platinum-Phosphorus (Pt-P) Lieb lattice, it has successfully overcome its structural instability and synthesized on a gold substrate via molecular beam epitaxy. Low-temperature scanning tunneling microscopy and spectroscopy verify the Lieb lattice's morphology and electronic flat bands. Furthermore, topological Dirac edge states stemming from pronounced spin-orbit coupling induced by heavy Pt atoms are predicted. These findings convincingly open perspectives for creating metal-inorganic framework-based atomic lattices, offering prospects for strongly correlated phases interplayed with topology.
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Affiliation(s)
- Wenjun Wu
- Department of Physics, Shanghai Key Laboratory of High Temperature Superconductors, Shanghai University, Shanghai, 200444, China
| | - Shuo Sun
- Department of Physics, Shanghai Key Laboratory of High Temperature Superconductors, Shanghai University, Shanghai, 200444, China
| | - Chi Sin Tang
- Singapore Synchrotron Light Source (SSLS), National University of Singapore, Singapore, 117603, Singapore
| | - Jing Wu
- Institute of Materials Research and Ring (IMRE), Agency for Science, Technology and Research (A*STAR), 2 Fusionopolis Way, Innovis #08-03, Singapore, 138634, Singapore
| | - Yu Ma
- Department of Physics, Shanghai Key Laboratory of High Temperature Superconductors, Shanghai University, Shanghai, 200444, China
| | - Lingfeng Zhang
- Department of Physics, Shanghai Key Laboratory of High Temperature Superconductors, Shanghai University, Shanghai, 200444, China
| | - Chuanbing Cai
- Department of Physics, Shanghai Key Laboratory of High Temperature Superconductors, Shanghai University, Shanghai, 200444, China
| | - Jianxin Zhong
- Center for Quantum Science and Technology, Department of Physics, Shanghai University, Shanghai, 200444, China
| | - Milorad V Milošević
- Department of Physics & NANOlab Center of Excellence, University of Antwerp, Groenenborgerlaan 171, Antwerp, B-2020, Belgium
| | - Andrew T S Wee
- Department of Physics, Faculty of Science, National University of Singapore, Singapore, 117542, Singapore
- Centre for Advanced 2D Materials and Graphene Research, National University of Singapore, Singapore, 117546, Singapore
| | - Xinmao Yin
- Department of Physics, Shanghai Key Laboratory of High Temperature Superconductors, Shanghai University, Shanghai, 200444, China
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3
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Villalpando G, Jovanovic M, Hoff B, Jiang Y, Singha R, Yuan F, Hu H, Călugăru D, Mathur N, Khoury JF, Dulovic S, Singh B, Plisson VM, Pollak CJ, Moya JM, Burch KS, Bernevig BA, Schoop LM. Accessing bands with extended quantum metric in kagome Cs 2Ni 3S 4 through soft chemical processing. SCIENCE ADVANCES 2024; 10:eadl1103. [PMID: 39303043 DOI: 10.1126/sciadv.adl1103] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 09/28/2023] [Accepted: 08/15/2024] [Indexed: 09/22/2024]
Abstract
Flat bands that do not merely arise from weak interactions can produce exotic physical properties, such as superconductivity or correlated many-body effects. The quantum metric can differentiate whether flat bands will result in correlated physics or are merely dangling bonds. A potential avenue for achieving correlated flat bands involves leveraging geometrical constraints within specific lattice structures, such as the kagome lattice; however, materials are often more complex. In these cases, quantum geometry becomes a powerful indicator of the nature of bands with small dispersions. We present a simple, soft-chemical processing route to access a flat band with an extended quantum metric below the Fermi level. By oxidizing Ni-kagome material Cs2Ni3S4 to CsNi3S4, we see a two orders of magnitude drop in the room temperature resistance. However, CsNi3S4 is still insulating, with no evidence of a phase transition. Using experimental data, density functional theory calculations, and symmetry analysis, our results suggest the emergence of a correlated insulating state of unknown origin.
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Affiliation(s)
| | - Milena Jovanovic
- Department of Chemistry, Princeton University, Princeton, NJ 08544, USA
- Department of Chemistry, North Carolina State University, Raleigh, NC 27606, USA
| | - Brianna Hoff
- Department of Chemistry, Princeton University, Princeton, NJ 08544, USA
| | - Yi Jiang
- Donostia International Physics Center (DIPC), Paseo Manuel de Lardizábal, 20018 San Sebastián, Spain
| | - Ratnadwip Singha
- Department of Chemistry, Princeton University, Princeton, NJ 08544, USA
- Department of Physics, Indian Institute of Technology Guwahati, Assam 781039, India
| | - Fang Yuan
- Department of Chemistry, Princeton University, Princeton, NJ 08544, USA
| | - Haoyu Hu
- Donostia International Physics Center (DIPC), Paseo Manuel de Lardizábal, 20018 San Sebastián, Spain
| | - Dumitru Călugăru
- Department of Physics, Princeton University, Princeton, NJ 08544, USA
| | - Nitish Mathur
- Department of Chemistry, Princeton University, Princeton, NJ 08544, USA
| | - Jason F Khoury
- Department of Chemistry, Princeton University, Princeton, NJ 08544, USA
- School of Molecular Sciences, Arizona State University, Tempe, Arizona, 85287, United States
| | - Stephanie Dulovic
- Department of Chemistry, Princeton University, Princeton, NJ 08544, USA
| | - Birender Singh
- Department of Physics, Boston College, Chestnut Hill, MA 02467, USA
| | | | - Connor J Pollak
- Department of Chemistry, Princeton University, Princeton, NJ 08544, USA
| | - Jaime M Moya
- Department of Chemistry, Princeton University, Princeton, NJ 08544, USA
| | - Kenneth S Burch
- Department of Physics, Boston College, Chestnut Hill, MA 02467, USA
| | - B Andrei Bernevig
- Donostia International Physics Center (DIPC), Paseo Manuel de Lardizábal, 20018 San Sebastián, Spain
- Department of Physics, Princeton University, Princeton, NJ 08544, USA
- IKERBASQUE, Basque Foundation for Science, 48013 Bilbao, Spain
| | - Leslie M Schoop
- Department of Chemistry, Princeton University, Princeton, NJ 08544, USA
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4
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Lin R, Ramires A, Chitra R. Decoding the Drive-Bath Interplay: A Guideline to Enhance Superconductivity. PHYSICAL REVIEW LETTERS 2024; 133:086001. [PMID: 39241739 DOI: 10.1103/physrevlett.133.086001] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 06/07/2023] [Revised: 10/19/2023] [Accepted: 06/20/2024] [Indexed: 09/09/2024]
Abstract
Driven-dissipative physics lie at the core of quantum optics. However, the full interplay between a driven quantum many-body system and its environment remains relatively unexplored in the solid state realm. In this Letter, we inspect this interplay beyond the commonly employed stroboscopic Hamiltonian picture based on the specific example of a driven superconductor. Using the Shirley-Floquet and Keldysh formalisms as well as a generalization of the notion of superconducting fitness to the driven case, we show how a drive which anticommutes with the superconducting gap operator generically induces an unusual particle-hole structure in the spectral functions from the perspective of the thermal bath. Concomitant with a driving frequency which is near resonant with the intrinsic cutoff frequency of the underlying interaction, this spectral structure can be harnessed to enhance the superconducting transition temperature. Our work paves the way for further studies for driven-dissipative engineering of exotic phases of matter in solid-state systems.
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5
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Wang HC, Rauch T, Tellez-Mora A, Wirtz L, Romero AH, Marques MAL. Exploring flat-band properties in two-dimensional M 3QX 7 compounds. Phys Chem Chem Phys 2024; 26:21558-21567. [PMID: 39082370 DOI: 10.1039/d4cp01196a] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 08/15/2024]
Abstract
We present a computational study of the M3QX7 family of two-dimensional compounds, focusing specifically on their flat-band properties. We use a high-throughput search methodology, accelerated by machine learning, to explore the vast chemical space spawned by this family. In this way, we identify numerous stable 2D compounds within the M3QX7 family. We investigate how the chemical composition can be manipulated to modulate the position and dispersion of the flat bands. By employing a tight-binding model we explain the formation of flat bands as a result of a relatively loose connection between triangular M3QX3 clusters via bridges of X atoms. The model provides an understanding of the residual interactions that can impact the band dispersion. The same loose connection between clusters not only leads to strongly localized electronic states and thus flat electronic bands but also leads to localized phonon modes and flat bands in the phonon dispersion.
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Affiliation(s)
- Hai-Chen Wang
- Research Center Future Energy Materials and Systems of the University Alliance Ruhr, Faculty of Mechanical Engineering, Ruhr University Bochum, Universitätsstraße 150, D-44801 Bochum, Germany.
| | - Tomáš Rauch
- Friedrich-Schiller-University Jena, 07743 Jena, Germany
| | - Andres Tellez-Mora
- Department of Physics, West Virginia University, Morgantown, WV 26506, USA.
| | - Ludger Wirtz
- Department of Physics and Materials Science, University of Luxembourg, 162a avenue de la Faïencerie, L-1511 Luxembourg, Luxembourg
| | - Aldo H Romero
- Department of Physics, West Virginia University, Morgantown, WV 26506, USA.
- Department of Physics and Materials Science, University of Luxembourg, 162a avenue de la Faïencerie, L-1511 Luxembourg, Luxembourg
| | - Miguel A L Marques
- Research Center Future Energy Materials and Systems of the University Alliance Ruhr, Faculty of Mechanical Engineering, Ruhr University Bochum, Universitätsstraße 150, D-44801 Bochum, Germany.
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6
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Chen L, Xie F, Sur S, Hu H, Paschen S, Cano J, Si Q. Emergent flat band and topological Kondo semimetal driven by orbital-selective correlations. Nat Commun 2024; 15:5242. [PMID: 38898039 PMCID: PMC11186837 DOI: 10.1038/s41467-024-49306-w] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/24/2023] [Accepted: 05/30/2024] [Indexed: 06/21/2024] Open
Abstract
Flat electronic bands are expected to show proportionally enhanced electron correlations, which may generate a plethora of novel quantum phases and unusual low-energy excitations. They are increasingly being pursued in d-electron-based systems with crystalline lattices that feature destructive electronic interference, where they are often topological. Such flat bands, though, are generically located far away from the Fermi energy, which limits their capacity to partake in the low-energy physics. Here we show that electron correlations produce emergent flat bands that are pinned to the Fermi energy. We demonstrate this effect within a Hubbard model, in the regime described by Wannier orbitals where an effective Kondo description arises through orbital-selective Mott correlations. Moreover, the correlation effect cooperates with symmetry constraints to produce a topological Kondo semimetal. Our results motivate a novel design principle for Weyl Kondo semimetals in a new setting, viz. d-electron-based materials on suitable crystal lattices, and uncover interconnections among seemingly disparate systems that may inspire fresh understandings and realizations of correlated topological effects in quantum materials and beyond.
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Affiliation(s)
- Lei Chen
- Department of Physics and Astronomy, Rice Center for Quantum Materials, Rice University, Houston, TX, 77005, USA
| | - Fang Xie
- Department of Physics and Astronomy, Rice Center for Quantum Materials, Rice University, Houston, TX, 77005, USA
| | - Shouvik Sur
- Department of Physics and Astronomy, Rice Center for Quantum Materials, Rice University, Houston, TX, 77005, USA
| | - Haoyu Hu
- Department of Physics and Astronomy, Rice Center for Quantum Materials, Rice University, Houston, TX, 77005, USA
- Donostia International Physics Center, P. Manuel de Lardizabal 4, 20018, Donostia-San Sebastian, Spain
| | - Silke Paschen
- Department of Physics and Astronomy, Rice Center for Quantum Materials, Rice University, Houston, TX, 77005, USA
- Institute of Solid State Physics, Vienna University of Technology, Wiedner Hauptstr. 8-10, 1040, Vienna, Austria
| | - Jennifer Cano
- Department of Physics and Astronomy, Stony Brook University, Stony Brook, NY, 11794, USA
- Center for Computational Quantum Physics, Flatiron Institute, New York, NY, 10010, USA
| | - Qimiao Si
- Department of Physics and Astronomy, Rice Center for Quantum Materials, Rice University, Houston, TX, 77005, USA.
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7
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Xing D, Tong B, Pan S, Wang Z, Luo J, Zhang J, Zhang CL. Rashba-splitting-induced topological flat band detected by anomalous resistance oscillations beyond the quantum limit in ZrTe 5. Nat Commun 2024; 15:4407. [PMID: 38782885 PMCID: PMC11116540 DOI: 10.1038/s41467-024-48761-9] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/29/2023] [Accepted: 05/14/2024] [Indexed: 05/25/2024] Open
Abstract
Topological flat bands - where the kinetic energy of electrons is quenched - provide a platform for investigating the topological properties of correlated systems. Here, we report the observation of a topological flat band formed by polar-distortion-assisted Rashba splitting in the three-dimensional Dirac material ZrTe5. The polar distortion and resulting Rashba splitting on the band are directly detected by torque magnetometry and the anomalous Hall effect, respectively. The local symmetry breaking further flattens the band, on which we observe resistance oscillations beyond the quantum limit. These oscillations follow the temperature dependence of the Lifshitz-Kosevich formula but are evenly distributed in B instead of 1/B at high magnetic fields. Furthermore, the cyclotron mass gets anomalously enhanced about 102 times at fields ~ 20 T. Our results provide an intrinsic platform without invoking moiré or order-stacking engineering, which opens the door for studying topologically correlated phenomena beyond two dimensions.
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Affiliation(s)
- Dong Xing
- Beijing National Laboratory for Condensed Matter Physics, Institute of Physics, Chinese Academy of Sciences, Beijing, 100190, China
- School of Physical Sciences, University of Chinese Academy of Sciences, Beijing, 100049, China
| | - Bingbing Tong
- Beijing National Laboratory for Condensed Matter Physics, Institute of Physics, Chinese Academy of Sciences, Beijing, 100190, China
| | - Senyang Pan
- High Magnetic Field Laboratory, HFIPS, Chinese Academy of Sciences, Hefei, 230031, China
| | - Zezhi Wang
- Beijing National Laboratory for Condensed Matter Physics, Institute of Physics, Chinese Academy of Sciences, Beijing, 100190, China
- School of Physical Sciences, University of Chinese Academy of Sciences, Beijing, 100049, China
| | - Jianlin Luo
- Beijing National Laboratory for Condensed Matter Physics, Institute of Physics, Chinese Academy of Sciences, Beijing, 100190, China
- School of Physical Sciences, University of Chinese Academy of Sciences, Beijing, 100049, China
| | - Jinglei Zhang
- High Magnetic Field Laboratory, HFIPS, Chinese Academy of Sciences, Hefei, 230031, China
| | - Cheng-Long Zhang
- Beijing National Laboratory for Condensed Matter Physics, Institute of Physics, Chinese Academy of Sciences, Beijing, 100190, China.
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8
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Jiang L, Fan FR, Chen D, Mu Q, Wang Y, Yue X, Li N, Sun Y, Li Q, Wu D, Zhou Y, Sun X, Liang H. Anomalous Hall effect and magnetic transition in the kagome material YbMn 6Sn 6. JOURNAL OF PHYSICS. CONDENSED MATTER : AN INSTITUTE OF PHYSICS JOURNAL 2024; 36:315701. [PMID: 38657636 DOI: 10.1088/1361-648x/ad42ef] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 01/19/2024] [Accepted: 04/24/2024] [Indexed: 04/26/2024]
Abstract
We investigate the magnetic and transport properties of a kagome magnet YbMn6Sn6. We have grown YbMn6Sn6single crystals having a HfFe6Ge6type structure with ordered Yb and Sn atoms, which is different from the distorted structure previously reported. The single crystal undergoes a ferromagnetic phase transition around 300 K and a ferrimagnetic transition at approximately 30 K, and the magnetic transition at low temperature may be correlated to the ordered Yb sublattice. Negative magnetoresistance has been observed at high temperatures, while the positive magnetoresistance appears at 5 K when the current is oriented out of kagome plane. We observe a large anisotropic anomalous Hall effect with the intrinsic Hall contribution of 141 Ω-1cm-1forσzxintand 32 Ω-1cm-1forσxyint, respectively. These values are similar to those in YMn6Sn6with the same anisotropy. The magnetic transition and anomalous Hall behavior in YbMn6Sn6highlights the influence of the ordered Yb atoms and rare earth elements on its magnetic and transport properties.
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Affiliation(s)
- Lei Jiang
- Institute of Physical Science and Information Technology, Anhui University, Hefei, Anhui 230601, People's Republic of China
| | - Feng-Ren Fan
- Department of Physics, University of Hong Kong, Hong Kong Special Administrative Region of China, People's Republic of China
- HKU-UCAS Joint Institute of Theoretical and Computational Physics at Hong Kong, Hong Kong Special Administrative Region of China, People's Republic of China
| | - Dong Chen
- College of Physics, Qingdao University, Qingdao 266071, People's Republic of China
| | - Qingge Mu
- Institute of Physical Science and Information Technology, Anhui University, Hefei, Anhui 230601, People's Republic of China
| | - Yiyan Wang
- Institute of Physical Science and Information Technology, Anhui University, Hefei, Anhui 230601, People's Republic of China
| | - Xiaoyu Yue
- School of Optical and Electronic Information, Suzhou City University, Suzhou 215104, People's Republic of China
| | - Na Li
- Institute of Physical Science and Information Technology, Anhui University, Hefei, Anhui 230601, People's Republic of China
| | - Yan Sun
- Institute of Physical Science and Information Technology, Anhui University, Hefei, Anhui 230601, People's Republic of China
| | - Qiuju Li
- School of Physics & Materials Science, Anhui University, Hefei, Anhui 230601, People's Republic of China
| | - Dandan Wu
- Institute of Physical Science and Information Technology, Anhui University, Hefei, Anhui 230601, People's Republic of China
| | - Ying Zhou
- Institute of Physical Science and Information Technology, Anhui University, Hefei, Anhui 230601, People's Republic of China
| | - Xuefeng Sun
- Institute of Physical Science and Information Technology, Anhui University, Hefei, Anhui 230601, People's Republic of China
| | - Hui Liang
- Institute of Physical Science and Information Technology, Anhui University, Hefei, Anhui 230601, People's Republic of China
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9
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Wu H, Chen L, Malinowski P, Jang BG, Deng Q, Scott K, Huang J, Ruff JPC, He Y, Chen X, Hu C, Yue Z, Oh JS, Teng X, Guo Y, Klemm M, Shi C, Shi Y, Setty C, Werner T, Hashimoto M, Lu D, Yilmaz T, Vescovo E, Mo SK, Fedorov A, Denlinger JD, Xie Y, Gao B, Kono J, Dai P, Han Y, Xu X, Birgeneau RJ, Zhu JX, da Silva Neto EH, Wu L, Chu JH, Si Q, Yi M. Reversible non-volatile electronic switching in a near-room-temperature van der Waals ferromagnet. Nat Commun 2024; 15:2739. [PMID: 38548765 PMCID: PMC10978849 DOI: 10.1038/s41467-024-46862-z] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/28/2023] [Accepted: 03/13/2024] [Indexed: 04/01/2024] Open
Abstract
Non-volatile phase-change memory devices utilize local heating to toggle between crystalline and amorphous states with distinct electrical properties. Expanding on this kind of switching to two topologically distinct phases requires controlled non-volatile switching between two crystalline phases with distinct symmetries. Here, we report the observation of reversible and non-volatile switching between two stable and closely related crystal structures, with remarkably distinct electronic structures, in the near-room-temperature van der Waals ferromagnet Fe5-δGeTe2. We show that the switching is enabled by the ordering and disordering of Fe site vacancies that results in distinct crystalline symmetries of the two phases, which can be controlled by a thermal annealing and quenching method. The two phases are distinguished by the presence of topological nodal lines due to the preserved global inversion symmetry in the site-disordered phase, flat bands resulting from quantum destructive interference on a bipartite lattice, and broken inversion symmetry in the site-ordered phase.
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Affiliation(s)
- Han Wu
- Department of Physics and Astronomy and Rice Center for Quantum Materials, Rice University, Houston, TX, USA
| | - Lei Chen
- Department of Physics and Astronomy and Rice Center for Quantum Materials, Rice University, Houston, TX, USA
| | - Paul Malinowski
- Department of Physics, University of Washington, Seattle, WA, USA
| | - Bo Gyu Jang
- Theoretical Division and Center for Integrated Nanotechnologies, Los Alamos National Laboratory, Los Alamos, NM, USA
- Department of Advanced Materials Engineering for Information and Electronics, Kyung Hee University, Yongin, Republic of Korea
| | - Qinwen Deng
- Department of Physics and Astronomy, University of Pennsylvania, Philadelphia, PA, USA
| | - Kirsty Scott
- Department of Physics, Yale University, New Haven, CT, USA
- Energy Sciences Institute, Yale University, West Haven, CT, USA
- Department of Physics and Astronomy, University of California, Davis, CA, USA
- Department of Applied Physics, Yale University, New Haven, CT, USA
| | - Jianwei Huang
- Department of Physics and Astronomy and Rice Center for Quantum Materials, Rice University, Houston, TX, USA
| | - Jacob P C Ruff
- Cornell High Energy Synchrotron Source, Cornell University, Ithaca, NY, USA
| | - Yu He
- Department of Physics, University of California, Berkeley, CA, USA
| | - Xiang Chen
- Department of Physics, University of California, Berkeley, CA, USA
| | - Chaowei Hu
- Department of Physics, University of Washington, Seattle, WA, USA
- Department of Materials Science and Engineering, University of Washington, Seattle, WA, USA
| | - Ziqin Yue
- Department of Physics and Astronomy and Rice Center for Quantum Materials, Rice University, Houston, TX, USA
| | - Ji Seop Oh
- Department of Physics and Astronomy and Rice Center for Quantum Materials, Rice University, Houston, TX, USA
- Department of Materials Science and Engineering, University of Washington, Seattle, WA, USA
| | - Xiaokun Teng
- Department of Physics and Astronomy and Rice Center for Quantum Materials, Rice University, Houston, TX, USA
| | - Yucheng Guo
- Department of Physics and Astronomy and Rice Center for Quantum Materials, Rice University, Houston, TX, USA
| | - Mason Klemm
- Department of Physics and Astronomy and Rice Center for Quantum Materials, Rice University, Houston, TX, USA
| | - Chuqiao Shi
- Department of Materials Science and NanoEngineering, Rice University, Houston, TX, USA
| | - Yue Shi
- Department of Physics, University of Washington, Seattle, WA, USA
| | - Chandan Setty
- Department of Physics and Astronomy and Rice Center for Quantum Materials, Rice University, Houston, TX, USA
| | - Tyler Werner
- Department of Applied Physics, Yale University, New Haven, CT, USA
| | - Makoto Hashimoto
- Stanford Synchrotron Radiation Lightsource, SLAC National Accelerator Laboratory, Menlo Park, CA, USA
| | - Donghui Lu
- Stanford Synchrotron Radiation Lightsource, SLAC National Accelerator Laboratory, Menlo Park, CA, USA
| | - Turgut Yilmaz
- National Synchrotron Light Source II, Brookhaven National Lab, Upton, NY, USA
| | - Elio Vescovo
- National Synchrotron Light Source II, Brookhaven National Lab, Upton, NY, USA
| | - Sung-Kwan Mo
- Advanced Light Source, Lawrence Berkeley National Laboratory, Berkeley, CA, USA
| | - Alexei Fedorov
- Advanced Light Source, Lawrence Berkeley National Laboratory, Berkeley, CA, USA
| | | | - Yaofeng Xie
- Department of Physics and Astronomy and Rice Center for Quantum Materials, Rice University, Houston, TX, USA
| | - Bin Gao
- Department of Physics and Astronomy and Rice Center for Quantum Materials, Rice University, Houston, TX, USA
| | - Junichiro Kono
- Department of Physics and Astronomy and Rice Center for Quantum Materials, Rice University, Houston, TX, USA
- Department of Materials Science and NanoEngineering, Rice University, Houston, TX, USA
- Departments of Electrical and Computer Engineering, Rice University, Houston, TX, USA
| | - Pengcheng Dai
- Department of Physics and Astronomy and Rice Center for Quantum Materials, Rice University, Houston, TX, USA
| | - Yimo Han
- Department of Materials Science and NanoEngineering, Rice University, Houston, TX, USA
| | - Xiaodong Xu
- Department of Physics, University of Washington, Seattle, WA, USA
- Department of Materials Science and Engineering, University of Washington, Seattle, WA, USA
| | - Robert J Birgeneau
- Department of Physics, University of California, Berkeley, CA, USA
- Materials Sciences Division, Lawrence Berkeley National Laboratory, Berkeley, CA, USA
- Department of Materials Science and Engineering, University of California, Berkeley, CA, USA
| | - Jian-Xin Zhu
- Theoretical Division and Center for Integrated Nanotechnologies, Los Alamos National Laboratory, Los Alamos, NM, USA
| | - Eduardo H da Silva Neto
- Department of Physics, Yale University, New Haven, CT, USA
- Energy Sciences Institute, Yale University, West Haven, CT, USA
- Department of Physics and Astronomy, University of California, Davis, CA, USA
- Department of Applied Physics, Yale University, New Haven, CT, USA
| | - Liang Wu
- Department of Physics and Astronomy, University of Pennsylvania, Philadelphia, PA, USA
| | - Jiun-Haw Chu
- Department of Physics, University of Washington, Seattle, WA, USA
| | - Qimiao Si
- Department of Physics and Astronomy and Rice Center for Quantum Materials, Rice University, Houston, TX, USA
| | - Ming Yi
- Department of Physics and Astronomy and Rice Center for Quantum Materials, Rice University, Houston, TX, USA.
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10
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Khasanov R, Ruan BB, Shi YQ, Chen GF, Luetkens H, Ren ZA, Guguchia Z. Tuning of the flat band and its impact on superconductivity in Mo 5Si 3-xP x. Nat Commun 2024; 15:2197. [PMID: 38467628 PMCID: PMC10928102 DOI: 10.1038/s41467-024-46514-2] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/01/2023] [Accepted: 02/15/2024] [Indexed: 03/13/2024] Open
Abstract
The superconductivity in systems containing dispersionless (flat) bands is seemingly paradoxical, as traditional Bardeen-Cooper-Schrieffer theory requires an infinite enhancement of the carrier masses. However, the combination of flat and steep (dispersive) bands within the multiple band scenario might boost superconducting responses, potentially explaining high-temperature superconductivity in cuprates and metal hydrides. Here, we report on the magnetic penetration depths, the upper critical field, and the specific heat measurements, together with the first-principles calculations for the Mo5Si3-xPx superconducting family. The band structure features a flat band that gradually approaches the Fermi level as a function of phosphorus doping x, reaching the Fermi level at x ≃ 1.3. This leads to an abrupt change in nearly all superconducting quantities. The superfluid density data placed on the 'Uemura plot' results in two separated branches, thus indicating that the emergence of a flat band enhances correlations between conducting electrons.
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Affiliation(s)
- Rustem Khasanov
- Laboratory for Muon Spin Spectroscopy, Paul Scherrer Institute, CH-5232, Villigen PSI, Switzerland.
| | - Bin-Bin Ruan
- Institute of Physics and Beijing National Laboratory for Condensed Matter Physics, Chinese Academy of Sciences, 100190, Beijing, China.
| | - Yun-Qing Shi
- Institute of Physics and Beijing National Laboratory for Condensed Matter Physics, Chinese Academy of Sciences, 100190, Beijing, China
- School of Physical Sciences, University of Chinese Academy of Sciences, 100049, Beijing, China
| | - Gen-Fu Chen
- Institute of Physics and Beijing National Laboratory for Condensed Matter Physics, Chinese Academy of Sciences, 100190, Beijing, China
- School of Physical Sciences, University of Chinese Academy of Sciences, 100049, Beijing, China
| | - Hubertus Luetkens
- Laboratory for Muon Spin Spectroscopy, Paul Scherrer Institute, CH-5232, Villigen PSI, Switzerland
| | - Zhi-An Ren
- Institute of Physics and Beijing National Laboratory for Condensed Matter Physics, Chinese Academy of Sciences, 100190, Beijing, China
- School of Physical Sciences, University of Chinese Academy of Sciences, 100049, Beijing, China
| | - Zurab Guguchia
- Laboratory for Muon Spin Spectroscopy, Paul Scherrer Institute, CH-5232, Villigen PSI, Switzerland
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11
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Chen Y, Huang J, Jiang K, Hu J. Decoding flat bands from compact localized states. Sci Bull (Beijing) 2023; 68:3165-3171. [PMID: 38007328 DOI: 10.1016/j.scib.2023.11.032] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/19/2023] [Revised: 09/11/2023] [Accepted: 11/03/2023] [Indexed: 11/27/2023]
Abstract
The flat band system is an ideal quantum platform to investigate the kaleidoscope created by the electron-electron correlation effects. The central ingredient of realizing a flat band is to find its compact localized states. In this work, we develop a systematic way to generate compact localized states by designing destructive interference patterns from 1-dimensional chains. A variety of 2-dimensional new flat band systems are constructed with this method. Furthermore, we show that the method can be extended to generate the compact localized states in multi-orbital systems by carefully designing the block hopping scheme, as well as in quasicrystal and disorder systems.
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Affiliation(s)
- Yuge Chen
- Beijing National Laboratory for Condensed Matter Physics and Institute of Physics, Chinese Academy of Sciences, Beijing 100190, China
| | - Juntao Huang
- Beijing National Laboratory for Condensed Matter Physics and Institute of Physics, Chinese Academy of Sciences, Beijing 100190, China; School of Physical Sciences, University of Chinese Academy of Sciences, Beijing 100190, China
| | - Kun Jiang
- Beijing National Laboratory for Condensed Matter Physics and Institute of Physics, Chinese Academy of Sciences, Beijing 100190, China; School of Physical Sciences, University of Chinese Academy of Sciences, Beijing 100190, China.
| | - Jiangping Hu
- Beijing National Laboratory for Condensed Matter Physics and Institute of Physics, Chinese Academy of Sciences, Beijing 100190, China; Kavli Institute of Theoretical Sciences, University of Chinese Academy of Sciences, Beijing 100190, China.
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12
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Zhou X. Flat bands find another dimension for exotic physical phases. Nature 2023; 623:259-260. [PMID: 37938698 DOI: 10.1038/d41586-023-03286-x] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/09/2023]
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13
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Wakefield JP, Kang M, Neves PM, Oh D, Fang S, McTigue R, Frank Zhao SY, Lamichhane TN, Chen A, Lee S, Park S, Park JH, Jozwiak C, Bostwick A, Rotenberg E, Rajapitamahuni A, Vescovo E, McChesney JL, Graf D, Palmstrom JC, Suzuki T, Li M, Comin R, Checkelsky JG. Three-dimensional flat bands in pyrochlore metal CaNi 2. Nature 2023; 623:301-306. [PMID: 37938707 DOI: 10.1038/s41586-023-06640-1] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/06/2023] [Accepted: 09/13/2023] [Indexed: 11/09/2023]
Abstract
Electronic flat-band materials host quantum states characterized by a quenched kinetic energy. These flat bands are often conducive to enhanced electron correlation effects and emergent quantum phases of matter1. Long studied in theoretical models2-4, these systems have received renewed interest after their experimental realization in van der Waals heterostructures5,6 and quasi-two-dimensional (2D) crystalline materials7,8. An outstanding experimental question is if such flat bands can be realized in three-dimensional (3D) networks, potentially enabling new materials platforms9,10 and phenomena11-13. Here we investigate the C15 Laves phase metal CaNi2, which contains a nickel pyrochlore lattice predicted at a model network level to host a doubly-degenerate, topological flat band arising from 3D destructive interference of electronic hopping14,15. Using angle-resolved photoemission spectroscopy, we observe a band with vanishing dispersion across the full 3D Brillouin zone that we identify with the pyrochlore flat band as well as two additional flat bands that we show arise from multi-orbital interference of Ni d-electrons. Furthermore, we demonstrate chemical tuning of the flat-band manifold to the Fermi level that coincides with enhanced electronic correlations and the appearance of superconductivity. Extending the notion of intrinsic band flatness from 2D to 3D, this provides a potential pathway to correlated behaviour predicted for higher-dimensional flat-band systems ranging from tunable topological15 to fractionalized phases16.
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Affiliation(s)
- Joshua P Wakefield
- Department of Physics, Massachusetts Institute of Technology, Cambridge, MA, USA
| | - Mingu Kang
- Department of Physics, Massachusetts Institute of Technology, Cambridge, MA, USA
- Center for Complex Phase Materials, Max Planck POSTECH/Korea Research Initiative, Pohang, Republic of Korea
| | - Paul M Neves
- Department of Physics, Massachusetts Institute of Technology, Cambridge, MA, USA
| | - Dongjin Oh
- Department of Physics, Massachusetts Institute of Technology, Cambridge, MA, USA
| | - Shiang Fang
- Department of Physics, Massachusetts Institute of Technology, Cambridge, MA, USA
| | - Ryan McTigue
- Department of Physics, Massachusetts Institute of Technology, Cambridge, MA, USA
| | - S Y Frank Zhao
- Department of Physics, Massachusetts Institute of Technology, Cambridge, MA, USA
| | - Tej N Lamichhane
- Department of Nuclear Science and Engineering, Massachusetts Institute of Technology, Cambridge, MA, USA
| | - Alan Chen
- Department of Physics, Massachusetts Institute of Technology, Cambridge, MA, USA
| | - Seongyong Lee
- Center for Complex Phase Materials, Max Planck POSTECH/Korea Research Initiative, Pohang, Republic of Korea
- Department of Physics, Pohang University of Science and Technology, Pohang, Republic of Korea
| | - Sudong Park
- Center for Complex Phase Materials, Max Planck POSTECH/Korea Research Initiative, Pohang, Republic of Korea
- Department of Physics, Pohang University of Science and Technology, Pohang, Republic of Korea
| | - Jae-Hoon Park
- Center for Complex Phase Materials, Max Planck POSTECH/Korea Research Initiative, Pohang, Republic of Korea
- Department of Physics, Pohang University of Science and Technology, Pohang, Republic of Korea
| | - Chris Jozwiak
- Advanced Light Source, Lawrence Berkeley National Laboratory, Berkeley, CA, USA
| | - Aaron Bostwick
- Advanced Light Source, Lawrence Berkeley National Laboratory, Berkeley, CA, USA
| | - Eli Rotenberg
- Advanced Light Source, Lawrence Berkeley National Laboratory, Berkeley, CA, USA
| | - Anil Rajapitamahuni
- National Synchrotron Light Source II, Brookhaven National Laboratory, Upton, NY, USA
| | - Elio Vescovo
- National Synchrotron Light Source II, Brookhaven National Laboratory, Upton, NY, USA
| | - Jessica L McChesney
- X-ray Science Division, Advanced Photon Source, Argonne National Laboratory, Lemont, IL, USA
| | - David Graf
- National High Magnetic Field Laboratory, Tallahassee, FL, USA
| | | | | | - Mingda Li
- Department of Nuclear Science and Engineering, Massachusetts Institute of Technology, Cambridge, MA, USA
| | - Riccardo Comin
- Department of Physics, Massachusetts Institute of Technology, Cambridge, MA, USA.
| | - Joseph G Checkelsky
- Department of Physics, Massachusetts Institute of Technology, Cambridge, MA, USA.
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14
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Lyu X, Li Y, Jiang P, Zhang J, Liu X, Li X, Yang H, Lu G, Hu X, Peng L, Gong Q, Gao Y. Reveal Ultrafast Electron Relaxation across Sub-bands of Tellurium by Time- and Energy-Resolved Photoemission Microscopy. NANO LETTERS 2023; 23:9547-9554. [PMID: 37816225 DOI: 10.1021/acs.nanolett.3c03102] [Citation(s) in RCA: 2] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 10/12/2023]
Abstract
Exploring ultrafast carrier dynamics is crucial for the materials' fundamental properties and device design. In this work, we employ time- and energy-resolved photoemission electron microscopy with tunable pump wavelengths from visible to near-infrared to reveal the ultrafast carrier dynamics of the elemental semiconductor tellurium. We find that two discrete sub-bands around the Γ point of the conduction band are involved in excited-state electron ultrafast relaxation and reveal that hot electrons first go through ultrafast intra sub-band cooling on a time scale of about 0.3 ps and then transfer from the higher sub-band to the lower one on a time scale of approximately 1 ps. Additionally, theoretical calculations reveal that the lower one has flat-band characteristics, possessing a large density of states and a long electron lifetime. Our work demonstrates that TR- and ER-PEEM with broad tunable pump wavelengths are powerful techniques in revealing the details of ultrafast carrier dynamics in time and energy domains.
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Affiliation(s)
- Xiaying Lyu
- State Key Laboratory for Mesoscopic Physics & Department of Physics and Frontiers Science Center for Nano-optoelectronics, Peking University, Beijing 100871, China
| | - Yaolong Li
- State Key Laboratory for Mesoscopic Physics & Department of Physics and Frontiers Science Center for Nano-optoelectronics, Peking University, Beijing 100871, China
| | - Pengzuo Jiang
- State Key Laboratory for Mesoscopic Physics & Department of Physics and Frontiers Science Center for Nano-optoelectronics, Peking University, Beijing 100871, China
| | - Jianing Zhang
- State Key Laboratory for Mesoscopic Physics & Department of Physics and Frontiers Science Center for Nano-optoelectronics, Peking University, Beijing 100871, China
| | - Xiulan Liu
- State Key Laboratory for Mesoscopic Physics & Department of Physics and Frontiers Science Center for Nano-optoelectronics, Peking University, Beijing 100871, China
| | - Xiaofang Li
- State Key Laboratory for Mesoscopic Physics & Department of Physics and Frontiers Science Center for Nano-optoelectronics, Peking University, Beijing 100871, China
| | - Hong Yang
- State Key Laboratory for Mesoscopic Physics & Department of Physics and Frontiers Science Center for Nano-optoelectronics, Peking University, Beijing 100871, China
- Peking University Yangtze Delta Institute of Optoelectronics, Nantong, Jiangsu 226010, China
- Collaborative Innovation Center of Extreme Optics, Shanxi University, Taiyuan, Shanxi 030006, China
| | - Guowei Lu
- State Key Laboratory for Mesoscopic Physics & Department of Physics and Frontiers Science Center for Nano-optoelectronics, Peking University, Beijing 100871, China
- Peking University Yangtze Delta Institute of Optoelectronics, Nantong, Jiangsu 226010, China
- Collaborative Innovation Center of Extreme Optics, Shanxi University, Taiyuan, Shanxi 030006, China
| | - Xiaoyong Hu
- State Key Laboratory for Mesoscopic Physics & Department of Physics and Frontiers Science Center for Nano-optoelectronics, Peking University, Beijing 100871, China
- Peking University Yangtze Delta Institute of Optoelectronics, Nantong, Jiangsu 226010, China
- Collaborative Innovation Center of Extreme Optics, Shanxi University, Taiyuan, Shanxi 030006, China
| | - Liangyou Peng
- State Key Laboratory for Mesoscopic Physics & Department of Physics and Frontiers Science Center for Nano-optoelectronics, Peking University, Beijing 100871, China
- Peking University Yangtze Delta Institute of Optoelectronics, Nantong, Jiangsu 226010, China
- Collaborative Innovation Center of Extreme Optics, Shanxi University, Taiyuan, Shanxi 030006, China
| | - Qihuang Gong
- State Key Laboratory for Mesoscopic Physics & Department of Physics and Frontiers Science Center for Nano-optoelectronics, Peking University, Beijing 100871, China
- Peking University Yangtze Delta Institute of Optoelectronics, Nantong, Jiangsu 226010, China
- Collaborative Innovation Center of Extreme Optics, Shanxi University, Taiyuan, Shanxi 030006, China
| | - Yunan Gao
- State Key Laboratory for Mesoscopic Physics & Department of Physics and Frontiers Science Center for Nano-optoelectronics, Peking University, Beijing 100871, China
- Peking University Yangtze Delta Institute of Optoelectronics, Nantong, Jiangsu 226010, China
- Collaborative Innovation Center of Extreme Optics, Shanxi University, Taiyuan, Shanxi 030006, China
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15
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Jugovac M, Cojocariu I, Sánchez-Barriga J, Gargiani P, Valvidares M, Feyer V, Blügel S, Bihlmayer G, Perna P. Inducing Single Spin-Polarized Flat Bands in Monolayer Graphene. ADVANCED MATERIALS (DEERFIELD BEACH, FLA.) 2023; 35:e2301441. [PMID: 37036386 DOI: 10.1002/adma.202301441] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 02/14/2023] [Revised: 03/27/2023] [Indexed: 06/19/2023]
Abstract
Due to the fundamental and technological implications in driving the appearance of non-trivial, exotic topological spin textures and emerging symmetry-broken phases, flat electronic bands in 2D materials, including graphene, are nowadays a relevant topic in the field of spintronics. Here, via europium doping, single spin-polarized bands are generated in monolayer graphene supported by the Co(0001) surface. The doping is controlled by Eu positioning, allowing for the formation of aK ¯ $\bar{\mathrm{K}}$ -valley localized single spin-polarized low-dispersive parabolic band close to the Fermi energy when Eu is on top, and of a π* flat band with single spin character when Eu is intercalated underneath graphene. In the latter case, Eu also induces a bandgap opening at the Dirac point while the Eu 4f states act as a spin filter, splitting the π band into two spin-polarized branches. The generation of flat bands with single spin character, as revealed by the spin- and angle-resolved photoemission spectroscopy (ARPES) experiments, complemented by density functional theory (DFT) calculations, opens up new pathways toward the realization of spintronic devices exploiting such novel exotic electronic and magnetic states.
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Affiliation(s)
- Matteo Jugovac
- Elettra - Sincrotrone Trieste, S.S. 14 - km 163.5, Basovizza, 34149, Trieste, Italy
| | - Iulia Cojocariu
- Elettra - Sincrotrone Trieste, S.S. 14 - km 163.5, Basovizza, 34149, Trieste, Italy
- Peter Grünberg Institute (PGI-6), Forschungszentrum Jülich GmbH, 52425, Jülich, Germany
- Dipartimento di Fisica, Università degli studi di Trieste, Via A. Valerio 2, 34127, Trieste, Italy
| | - Jaime Sánchez-Barriga
- Helmholtz-Zentrum Berlin für Materialien und Energie, Elektronenspeicherring BESSY II, Albert-Einstein-Str. 15, 12489, Berlin, Germany
- IMDEA Nanociencia, Campus de Cantoblanco, c/ Faraday 9, 28049, Madrid, Spain
| | | | | | - Vitaliy Feyer
- Peter Grünberg Institute (PGI-6), Forschungszentrum Jülich GmbH, 52425, Jülich, Germany
| | - Stefan Blügel
- Peter Grünberg Institut and Institute for Advanced Simulation, Forschungszentrum Jülich and JARA, 52425, Jülich, Germany
| | - Gustav Bihlmayer
- Peter Grünberg Institut and Institute for Advanced Simulation, Forschungszentrum Jülich and JARA, 52425, Jülich, Germany
| | - Paolo Perna
- IMDEA Nanociencia, Campus de Cantoblanco, c/ Faraday 9, 28049, Madrid, Spain
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16
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Mandal M, Drucker NC, Siriviboon P, Nguyen T, Boonkird A, Lamichhane TN, Okabe R, Chotrattanapituk A, Li M. Topological Superconductors from a Materials Perspective. CHEMISTRY OF MATERIALS : A PUBLICATION OF THE AMERICAN CHEMICAL SOCIETY 2023; 35:6184-6200. [PMID: 37637011 PMCID: PMC10448998 DOI: 10.1021/acs.chemmater.3c00713] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/27/2023] [Revised: 07/12/2023] [Indexed: 08/29/2023]
Abstract
Topological superconductors (TSCs) have garnered significant research and industry attention in the past two decades. By hosting Majorana bound states which can be used as qubits that are robust against local perturbations, TSCs offer a promising platform toward (nonuniversal) topological quantum computation. However, there has been a scarcity of TSC candidates, and the experimental signatures that identify a TSC are often elusive. In this Perspective, after a short review of the TSC basics and theories, we provide an overview of the TSC materials candidates, including natural compounds and synthetic material systems. We further introduce various experimental techniques to probe TSCs, focusing on how a system is identified as a TSC candidate and why a conclusive answer is often challenging to draw. We conclude by calling for new experimental signatures and stronger computational support to accelerate the search for new TSC candidates.
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Affiliation(s)
- Manasi Mandal
- Quantum
Measurement Group, MIT, Cambridge, Massachusetts 02139, United States
- Department
of Nuclear Science and Engineering, MIT, Cambridge, Massachusetts 02139, United States
| | - Nathan C. Drucker
- Quantum
Measurement Group, MIT, Cambridge, Massachusetts 02139, United States
- School
of Engineering and Applied Sciences, Harvard
University, Cambridge, Massachusetts 02138, United States
| | - Phum Siriviboon
- Department
of Physics, MIT, Cambridge, Massachusetts 02139, United States
| | - Thanh Nguyen
- Quantum
Measurement Group, MIT, Cambridge, Massachusetts 02139, United States
- Department
of Nuclear Science and Engineering, MIT, Cambridge, Massachusetts 02139, United States
| | - Artittaya Boonkird
- Quantum
Measurement Group, MIT, Cambridge, Massachusetts 02139, United States
- Department
of Nuclear Science and Engineering, MIT, Cambridge, Massachusetts 02139, United States
| | - Tej Nath Lamichhane
- Quantum
Measurement Group, MIT, Cambridge, Massachusetts 02139, United States
- Department
of Nuclear Science and Engineering, MIT, Cambridge, Massachusetts 02139, United States
| | - Ryotaro Okabe
- Quantum
Measurement Group, MIT, Cambridge, Massachusetts 02139, United States
- Department
of Chemistry, MIT, Cambridge, Massachusetts 02139, United States
| | - Abhijatmedhi Chotrattanapituk
- Quantum
Measurement Group, MIT, Cambridge, Massachusetts 02139, United States
- Department
of Electrical Engineering and Computer Science, MIT, Cambridge, Massachusetts 02139, United States
| | - Mingda Li
- Quantum
Measurement Group, MIT, Cambridge, Massachusetts 02139, United States
- Department
of Nuclear Science and Engineering, MIT, Cambridge, Massachusetts 02139, United States
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17
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Li Y, Yuan Q, Guo D, Lou C, Cui X, Mei G, Petek H, Cao L, Ji W, Feng M. 1D Electronic Flat Bands in Untwisted Moiré Superlattices. ADVANCED MATERIALS (DEERFIELD BEACH, FLA.) 2023; 35:e2300572. [PMID: 37057612 DOI: 10.1002/adma.202300572] [Citation(s) in RCA: 3] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 01/18/2023] [Revised: 04/03/2023] [Indexed: 06/16/2023]
Abstract
After the preparation of 2D electronic flat band (EFB) in van der Waals (vdW) superlattices, recent measurements suggest the existence of 1D electronic flat bands (1D-EFBs) in twisted vdW bilayers. However, the realization of 1D-EFBs is experimentally elusive in untwisted 2D layers, which is desired considering their fabrication and scalability. Herein, the discovery of 1D-EFBs is reported in an untwisted in situ-grown two atomic-layer Bi(110) superlattice self-aligned on an SnSe(001) substrate using scanning probe microscopy measurements and density functional theory calculations. While the Bi-Bi dimers of Bi zigzag (ZZ) chains are buckled, the epitaxial lattice mismatch between the Bi and SnSe layers induces two 1D buckling reversal regions (BRRs) extending along the ZZ direction in each Bi(110)-11 × 11 supercell. A series of 1D-EFBs arises spatially following BRRs that isolate electronic states along the armchair (AC) direction and localize electrons in 1D extended states along ZZ due to quantum interference at a topological node. This work provides a generalized strategy for engineering 1D-EFBs in utilizing lattice mismatch between untwisted rectangular vdW layers.
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Affiliation(s)
- Yafei Li
- School of Physics and Technology and Key Laboratory of Artificial Micro- and Nano-Structures of Ministry of Education, Wuhan University, Wuhan, 430072, P. R. China
| | - Qing Yuan
- School of Physics and Technology and Key Laboratory of Artificial Micro- and Nano-Structures of Ministry of Education, Wuhan University, Wuhan, 430072, P. R. China
| | - Deping Guo
- Beijing Key Laboratory of Optoelectronic Functional Materials & Micro-Nano Devices, Department of Physics, Renmin University of China, Beijing, 100872, P. R. China
- Key Laboratory of Quantum State Construction and Manipulation (Ministry of Education), Renmin Universiry of China, Beijing, 100872, P. R. China
| | - Cancan Lou
- School of Physics and Technology and Key Laboratory of Artificial Micro- and Nano-Structures of Ministry of Education, Wuhan University, Wuhan, 430072, P. R. China
| | - Xingxia Cui
- School of Physics and Technology and Key Laboratory of Artificial Micro- and Nano-Structures of Ministry of Education, Wuhan University, Wuhan, 430072, P. R. China
| | - Guangqiang Mei
- School of Physics and Technology and Key Laboratory of Artificial Micro- and Nano-Structures of Ministry of Education, Wuhan University, Wuhan, 430072, P. R. China
| | - Hrvoje Petek
- Department of Physics and Astronomy and the IQ Initiative, University of Pittsburgh, Pittsburgh, 15260, USA
| | - Limin Cao
- School of Physics and Technology and Key Laboratory of Artificial Micro- and Nano-Structures of Ministry of Education, Wuhan University, Wuhan, 430072, P. R. China
| | - Wei Ji
- Beijing Key Laboratory of Optoelectronic Functional Materials & Micro-Nano Devices, Department of Physics, Renmin University of China, Beijing, 100872, P. R. China
- Key Laboratory of Quantum State Construction and Manipulation (Ministry of Education), Renmin Universiry of China, Beijing, 100872, P. R. China
| | - Min Feng
- School of Physics and Technology and Key Laboratory of Artificial Micro- and Nano-Structures of Ministry of Education, Wuhan University, Wuhan, 430072, P. R. China
- Institute for Advanced Study, Wuhan University, Wuhan, 430072, P. R. China
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18
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Banu S L, Veerapandy V, Fjellvåg H, Vajeeston P. First-Principles Insights into the Relative Stability, Physical Properties, and Chemical Properties of MoSe 2. ACS OMEGA 2023; 8:13799-13812. [PMID: 37091371 PMCID: PMC10116531 DOI: 10.1021/acsomega.2c08217] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 12/27/2022] [Accepted: 03/07/2023] [Indexed: 05/03/2023]
Abstract
A fascinating transition-metal dichalcogenide (TMDC) compound, MoSe2, has attracted a lot of interest in electrochemical, photocatalytic, and optoelectronic systems. However, detailed studies on the structural stability of the various MoSe2 polymorphs are still lacking. For the first time, the relative stability of 11 different MoSe2 polymorphs (1H, 2H, 3Ha, 3Hb, 2T, 4T, 2R1, 1T1, 1T2, 3T, and 2R2) is proposed, and a detailed analysis of these polymorphs is carried out by employing the first-principles calculations based on density functional theory (DFT). We computed the physical properties of the polymorphs such as band structure, phonon, and elastic constants to examine the viability for real-world applications. The electronic properties of the involved polymorphs were calculated by employing the hybrid functional of Heyd, Scuseria, and Ernzerhof (HSE06). The energy band gap of the polymorphs (1H, 2H, 3Ha, 3Hb, 2T, 4T, and 2R1) is in the range of 1.6-1.8 eV, coinciding with the experimental value for the polymorph 2H. The covalent bonding nature of MoSe2 is analyzed from the charge density, charge transfer, and electron localization function. Among the 11 polymorphs, 1H, 2H, 2T, and 3Hb polymorphs are predicted as stable polymorphs based on the calculation of the mechanical and dynamical properties. Even though the 4T and 3Ha polymorphs' phonons are stable, they are mechanically unstable; hence, they are considered to be under a metastable condition. Additionally, we computed the direction-dependent elastic moduli and isotropic factors for both mechanically and dynamically stable polymorphs. Stable polymorphs are analyzed spectroscopically using IR and Raman spectra. The thermal stability of the polymorphs is also studied.
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Affiliation(s)
- Lathifa Banu S
- Department
of Computational Physics, School of Physics, Madurai Kamaraj University, Palkalai Nagar, Madurai 625021, Tamil Nadu, India
| | - Vasu Veerapandy
- Department
of Computational Physics, School of Physics, Madurai Kamaraj University, Palkalai Nagar, Madurai 625021, Tamil Nadu, India
| | - Helmer Fjellvåg
- Department
of Chemistry and Center for Materials Science and Nanotechnology, University of Oslo, Oslo 0371, Norway
| | - Ponniah Vajeeston
- Department
of Chemistry and Center for Materials Science and Nanotechnology, University of Oslo, Oslo 0371, Norway
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19
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Hase I, Higashi Y, Eisaki H, Kawashima K. Flat band ferromagnetism in Pb[Formula: see text]Sb[Formula: see text]O[Formula: see text] via a self-doped mechanism. Sci Rep 2023; 13:4743. [PMID: 36959386 PMCID: PMC10036504 DOI: 10.1038/s41598-023-31917-w] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/18/2022] [Accepted: 03/20/2023] [Indexed: 03/25/2023] Open
Abstract
Electron systems with strong geometrical frustrations have flat bands, and their unusual band dispersions are expected to induce a wide variety of physical properties. However, for the emergence of such properties, the Fermi level must be pinned within the flat band. In this study, we performed first-principles calculations on pyrochlore oxide Pb[Formula: see text]Sb[Formula: see text]O[Formula: see text] and theoretically clarified that the self-doping mechanism induces pinning of the Fermi level in the flat band in this system. Therefore, a very high density of states is realized at the Fermi level, and the ferromagnetic state transforms into the ground state via a flat band mechanism, although the system does not contain any magnetic elements. This compound has the potential to serve as a new platform for projecting the properties of flat band systems in the real world.
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Affiliation(s)
- I. Hase
- National Institute of Advanced Industrial Science and Technology (AIST), Tsukuba Central 2, 1-1-1 Umezono, Tsukuba, 305-8568 Japan
| | - Y. Higashi
- National Institute of Advanced Industrial Science and Technology (AIST), Tsukuba Central 2, 1-1-1 Umezono, Tsukuba, 305-8568 Japan
| | - H. Eisaki
- National Institute of Advanced Industrial Science and Technology (AIST), Tsukuba Central 2, 1-1-1 Umezono, Tsukuba, 305-8568 Japan
| | - K. Kawashima
- IMRA-JAPAN Material R &D Co. Ltd., 2-1 Asahi-machi, Kariya, Aichi 448-0032 Japan
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20
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Kong W, Xiao X, Zhan F, Wang R, Gan LY, Wei J, Fan J, Wu X. A carbon allotrope with twisted Dirac cones induced by grain boundaries composed of pentagons and octagons. Phys Chem Chem Phys 2023; 25:4230-4235. [PMID: 36661111 DOI: 10.1039/d2cp05271g] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/21/2023]
Abstract
The grain boundaries (GBs) composed of pentagons and octagons (558 GBs) have been demonstrated to induce attractive transport properties such as Van Hove singularity (VHS) and quasi-one-dimensional metallic wires. Here, we propose a monolayer carbon allotrope which is formed from the introduction of periodic 558 GBs to decorate intact graphene, termed as PHO-graphene. The calculated electronic properties indicate that PHO-graphene not only inherits the previously superior characteristics such as Van Hove singularity and quasi-one-dimensional metallic wires, but also possesses two twisted Dirac cones near the Fermi level. Further calculation finds that the Berry phase is quantized to ± π at the two Dirac points, which is consistent with the distribution of the corresponding Berry curvature. The parity argument uncovers that PHO-graphene hosts a nontrivial band topology and the edge states connecting the two Dirac points are clearly visible. Our findings not only provide a reliable avenue to realize the abundant and extraordinary properties of carbon allotropes, but also offer an attractive approach for designing all carbon-based devices.
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Affiliation(s)
- Weixiang Kong
- Institute for Structure and Function and Department of Physics, Chongqing University, Chongqing 401331, People's Republic of China.
| | - Xiaoliang Xiao
- Institute for Structure and Function and Department of Physics, Chongqing University, Chongqing 401331, People's Republic of China.
| | - Fangyang Zhan
- Institute for Structure and Function and Department of Physics, Chongqing University, Chongqing 401331, People's Republic of China.
| | - Rui Wang
- Institute for Structure and Function and Department of Physics, Chongqing University, Chongqing 401331, People's Republic of China.
| | - Li-Yong Gan
- Institute for Structure and Function and Department of Physics, Chongqing University, Chongqing 401331, People's Republic of China.
| | - Juan Wei
- Institute for Structure and Function and Department of Physics, Chongqing University, Chongqing 401331, People's Republic of China.
| | - Jing Fan
- Center for Computational Science and Engineering, Southern University of Science and Technology, Shenzhen 518055, People's Republic of China
| | - Xiaozhi Wu
- Institute for Structure and Function and Department of Physics, Chongqing University, Chongqing 401331, People's Republic of China.
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21
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Xu Z, Kong X, Chang J, Sievenpiper DF, Cui TJ. Topological Flat Bands in Self-Complementary Plasmonic Metasurfaces. PHYSICAL REVIEW LETTERS 2022; 129:253001. [PMID: 36608243 DOI: 10.1103/physrevlett.129.253001] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 06/06/2022] [Revised: 10/09/2022] [Accepted: 11/15/2022] [Indexed: 06/17/2023]
Abstract
Photonics can be confined in real space with dispersion vanishing in the momentum space due to destructive interference. In this Letter, we report the experimental realization of flat bands with nontrivial topology in a self-complementary plasmonic metasurface. The band diagram and compact localized states are measured. In these nontrivial band gaps, we observe the topological edge states by near-field measurements. Furthermore, we propose a digitalized metasurface by loading controllable diodes with C_{3} symmetry in every unit cell. By pumping a digital signal into the metasurface, we investigate the interaction between incident waves and the dynamic metasurface. Experimental results indicate that compact localized states in the nontrivial flat band could enhance the wave-matter interactions to convert more incident waves to time-modulated harmonic photonics. Although our experiments are conducted in the microwave regime, extending the related concepts into the optical plasmonic systems is feasible. Our findings pave an avenue toward planar integrated photonic devices with nontrivial flat bands and exotic transmission phenomena.
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Affiliation(s)
- Zhixia Xu
- State Key Laboratory of Millimeter Waves, Southeast University, Nanjing 210096, China
- School of Information Science and Technology, Dalian Maritime University, Dalian 116026, China
| | - Xianghong Kong
- Department of Electrical and Computer Engineering, National University of Singapore, Singapore 117583, Singapore
| | - Jie Chang
- School of Information Science and Technology, Dalian Maritime University, Dalian 116026, China
| | - Daniel F Sievenpiper
- Electrical and Computer Engineering Department, University of California San Diego, San Diego, California 92093, USA
| | - Tie Jun Cui
- State Key Laboratory of Millimeter Waves, Southeast University, Nanjing 210096, China
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22
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Abstract
A kagome lattice naturally features Dirac fermions, flat bands and van Hove singularities in its electronic structure. The Dirac fermions encode topology, flat bands favour correlated phenomena such as magnetism, and van Hove singularities can lead to instabilities towards long-range many-body orders, altogether allowing for the realization and discovery of a series of topological kagome magnets and superconductors with exotic properties. Recent progress in exploring kagome materials has revealed rich emergent phenomena resulting from the quantum interactions between geometry, topology, spin and correlation. Here we review these key developments in this field, starting from the fundamental concepts of a kagome lattice, to the realizations of Chern and Weyl topological magnetism, to various flat-band many-body correlations, and then to the puzzles of unconventional charge-density waves and superconductivity. We highlight the connection between theoretical ideas and experimental observations, and the bond between quantum interactions within kagome magnets and kagome superconductors, as well as their relation to the concepts in topological insulators, topological superconductors, Weyl semimetals and high-temperature superconductors. These developments broadly bridge topological quantum physics and correlated many-body physics in a wide range of bulk materials and substantially advance the frontier of topological quantum matter.
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23
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Liu Y, Huang H, Yuan J, Zhang Y, Feng H, Chen N, Li Y, Teng J, Jin K, Xue D, Su Y. Upper limit of the transition temperature of superconducting materials. PATTERNS (NEW YORK, N.Y.) 2022; 3:100609. [PMID: 36419453 PMCID: PMC9676523 DOI: 10.1016/j.patter.2022.100609] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 03/12/2022] [Revised: 08/05/2022] [Accepted: 09/21/2022] [Indexed: 11/12/2022]
Abstract
Why are the transition temperatures (T c) of superconducting materials so different? The answer to this question is not only of great significance in revealing the mechanism of high-T c superconductivity but also can be used as a guide for the design of new superconductors. However, so far, it is still challenging to identify the governing factors affecting the T c. In this work, with the aid of machine learning and first-principles calculations, we found a close relevance between the upper limit of the T c and the energy-level distribution of valence electrons. It implies that some additional inter-orbital electron-electron interaction should be considered in the interpretation of high-T c superconductivity.
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Affiliation(s)
- Yang Liu
- Beijing Advanced Innovation Center for Materials Genome Engineering, University of Science and Technology Beijing, Beijing 100083, China
- Institute for Advanced Materials and Technology, University of Science and Technology Beijing, Beijing 100083, China
- Institute of Physics, Chinese Academy of Sciences, Beijing 100190, China
| | - Haiyou Huang
- Beijing Advanced Innovation Center for Materials Genome Engineering, University of Science and Technology Beijing, Beijing 100083, China
- Institute for Advanced Materials and Technology, University of Science and Technology Beijing, Beijing 100083, China
| | - Jie Yuan
- Institute of Physics, Chinese Academy of Sciences, Beijing 100190, China
| | - Yan Zhang
- Beijing Advanced Innovation Center for Materials Genome Engineering, University of Science and Technology Beijing, Beijing 100083, China
- Institute for Advanced Materials and Technology, University of Science and Technology Beijing, Beijing 100083, China
| | - Hongyuan Feng
- Beijing Advanced Innovation Center for Materials Genome Engineering, University of Science and Technology Beijing, Beijing 100083, China
- Institute for Advanced Materials and Technology, University of Science and Technology Beijing, Beijing 100083, China
| | - Ning Chen
- School of Materials Science and Engineering, University of Science and Technology Beijing, Beijing 100083, China
| | - Yang Li
- Department of Engineering Science and Materials, University of Puerto Rico, Mayaguez, PR 00681-9000, USA
| | - Jiao Teng
- School of Materials Science and Engineering, University of Science and Technology Beijing, Beijing 100083, China
| | - Kui Jin
- Institute of Physics, Chinese Academy of Sciences, Beijing 100190, China
| | - Dezhen Xue
- State Key Laboratory for Mechanical Behavior of Materials, Xi’an Jiaotong University, Xi’an 710049, China
| | - Yanjing Su
- Beijing Advanced Innovation Center for Materials Genome Engineering, University of Science and Technology Beijing, Beijing 100083, China
- Institute for Advanced Materials and Technology, University of Science and Technology Beijing, Beijing 100083, China
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24
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Tang F, Ono S, Wan X, Watanabe H. High-Throughput Investigations of Topological and Nodal Superconductors. PHYSICAL REVIEW LETTERS 2022; 129:027001. [PMID: 35867454 DOI: 10.1103/physrevlett.129.027001] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 11/02/2021] [Revised: 03/01/2022] [Accepted: 05/27/2022] [Indexed: 06/15/2023]
Abstract
The theory of symmetry indicators has enabled database searches for topological materials in normal conducting phases, which has led to several encyclopedic topological material databases. To date, such a database for topological superconductors is yet to be achieved because of the lack of information about pairing symmetries of realistic materials. In this Letter, sidestepping this issue, we tackle an alternative problem: the predictions of topological and nodal superconductivity in materials for each single-valued representation of point groups. Based on recently developed symmetry indicators for superconductors, we provide comprehensive mappings from pairing symmetries to the topological or nodal superconducting nature for nonmagnetic materials listed in the Inorganic Crystal Structure Database. We quantitatively show that around 90% of computed materials are topological or nodal superconductors when a pairing that belongs to a one-dimensional nontrivial representation of point groups is assumed. When materials are representation-enforced nodal superconductors, positions and shapes of the nodes are also identified. When combined with experiments, our results will help us understand the pairing mechanism and facilitate realizations of the long-sought Majorana fermions promising for topological quantum computations.
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Affiliation(s)
- Feng Tang
- National Laboratory of Solid State Microstructures and School of Physics, Nanjing University, Nanjing 210093, China and Collaborative Innovation Center of Advanced Microstructures, Nanjing University, Nanjing 210093, China
| | - Seishiro Ono
- Department of Applied Physics, University of Tokyo, Tokyo 113-8656, Japan
| | - Xiangang Wan
- National Laboratory of Solid State Microstructures and School of Physics, Nanjing University, Nanjing 210093, China and Collaborative Innovation Center of Advanced Microstructures, Nanjing University, Nanjing 210093, China
| | - Haruki Watanabe
- Department of Applied Physics, University of Tokyo, Tokyo 113-8656, Japan
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25
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Peculiar Physics of Heavy-Fermion Metals: Theory versus Experiment. ATOMS 2022. [DOI: 10.3390/atoms10030067] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/01/2023] Open
Abstract
This review considers the topological fermion condensation quantum phase transition (FCQPT) that leads to flat bands and allows the elucidation of the special behavior of heavy-fermion (HF) metals that is not exhibited by common metals described within the framework of the Landau Fermi liquid (LFL) theory. We bring together theoretical consideration within the framework of the fermion condensation theory based on the FCQPT with experimental data collected on HF metals. We show that very different HF metals demonstrate universal behavior induced by the FCQPT and demonstrate that Fermi systems near the FCQPT are controlled by the Fermi quasiparticles with the effective mass M* strongly depending on temperature T, magnetic field B, pressure P, etc. Within the framework of our analysis, the experimental data regarding the thermodynamic, transport and relaxation properties of HF metal are naturally described. Based on the theory, we explain a number of experimental data and show that the considered HF metals exhibit peculiar properties such as: (1) the universal T/B scaling behavior; (2) the linear dependence of the resistivity on T, ρ(T)∝A1T (with A1 is a temperature-independent coefficient), and the negative magnetoresistance; (3) asymmetrical dependence of the tunneling differential conductivity (resistivity) on the bias voltage; (4) in the case of a flat band, the superconducting critical temperature Tc∝g with g being the coupling constant, while the M* becomes finite; (5) we show that the so called Planckian limit exhibited by HF metals with ρ(T)∝T is defined by the presence of flat bands.
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26
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Jovanovic M, Schoop LM. Simple Chemical Rules for Predicting Band Structures of Kagome Materials. J Am Chem Soc 2022; 144:10978-10991. [PMID: 35675484 DOI: 10.1021/jacs.2c04183] [Citation(s) in RCA: 5] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Abstract
Compounds featuring a kagome lattice are studied for a wide range of properties, from localized magnetism to massless and massive Dirac Fermions. These properties come from the symmetry of the kagome lattice, which gives rise to Dirac cones and flat bands. However, not all compounds with a kagome sublattice show properties related to it. We derive chemical rules predicting if the low-energy physics of a material is determined by the kagome sublattice and bands arising from it. After sorting out all known crystals with the kagome lattice into four groups, we use chemical heuristics and local symmetry to explain additional conditions that need to be met to have kagome bands near the Fermi level.
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Affiliation(s)
- Milena Jovanovic
- Department of Chemistry, Princeton University, Princeton, New Jersey 08544, United States
| | - Leslie M Schoop
- Department of Chemistry, Princeton University, Princeton, New Jersey 08544, United States
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27
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Guo S, Mitchell Warden HE, Cava RJ. Structural Diversity in Oxoiridates with 1D Ir nO 3(n+1) Chain Fragments and Flat Bands. Inorg Chem 2022; 61:10043-10050. [PMID: 35709355 DOI: 10.1021/acs.inorgchem.2c00957] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Abstract
A previously unreported series of hexagonal-perovskite-based Rb-oxoiridates, Rb5Ir2O9, Rb7Ir3O12, and Rb12Ir7O24, have been synthesized and structurally analyzed via N2-protected single-crystal X-ray diffraction (SC-XRD). These materials exhibit different 1D IrnO3(n+1) chain fragments along their c axes. IrO6 octahedra and RbOx (x = 6, 8, and 10) polyhedra are their basic building blocks. The IrO6 octahedra are linked via face-sharing, forming Ir2O9 dimers, Ir3O12 trimers, and Ir7O24 heptamers. The nonmagnetic RbOx (x = 6, 8, and 10) polyhedra serve as both bridging units and spacers. Temperature-dependent SC-XRD shows all three to display positive thermal expansion and rules out structural transitions from their triangular symmetries down to 100 K. Density functional theory results suggest semiconducting-like behavior for the title compounds. The flatness of the electronic bands and our structural analysis are of potential interest for understanding and designing 1D quantum materials.
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Affiliation(s)
- Shu Guo
- Department of Chemistry, Princeton University, Princeton, New Jersey 08544, United States
| | | | - R J Cava
- Department of Chemistry, Princeton University, Princeton, New Jersey 08544, United States
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28
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Strongly Correlated Quantum Spin Liquids versus Heavy Fermion Metals: A Review. MATERIALS 2022; 15:ma15113901. [PMID: 35683199 PMCID: PMC9182384 DOI: 10.3390/ma15113901] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 04/03/2022] [Revised: 05/15/2022] [Accepted: 05/25/2022] [Indexed: 12/04/2022]
Abstract
This review considers the topological fermion condensation quantum phase transition (FCQPT) that explains the complex behavior of strongly correlated Fermi systems, such as frustrated insulators with quantum spin liquid and heavy fermion metals. The review contrasts theoretical consideration with recent experimental data collected on both heavy fermion metals (HF) and frustrated insulators. Such a method allows to understand experimental data. We also consider experimental data collected on quantum spin liquid in Lu3Cu2Sb3O14 and quasi-one dimensional (1D) quantum spin liquid in both YbAlO3 and Cu(C4H4N2)(NO3)2 with the aim to establish a sound theoretical explanation for the observed scaling laws, Landau Fermi liquid (LFL) and non-Fermi-liquid (NFL) behavior exhibited by these frustrated insulators. The recent experimental data on the heavy-fermion metal α−YbAl1−xFexB4, with x=0.014, and on its sister compounds β−YbAlB4 and YbCo2Ge4, carried out under the application of magnetic field as a control parameter are analyzed. We show that the thermodynamic and transport properties as well as the empirical scaling laws follow from the fermion condensation theory. We explain how both the similarity and the difference in the thermodynamic and transport properties of α−YbAl1−xFexB4 and in its sister compounds β−YbAlB4 and YbCo2Ge4 emerge, as well as establish connection of these (HF) metals with insulators Lu3Cu2Sb3O14, Cu(C4H4N2)(NO3)2 and YbAlO3. We demonstrate that the universal LFL and NFL behavior emerge because the HF compounds and the frustrated insulators are located near the topological FCQPT or are driven by the application of magnetic fields.
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29
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Khoury JF, Han B, Jovanovic M, Singha R, Song X, Queiroz R, Ong NP, Schoop LM. A Class of Magnetic Topological Material Candidates with Hypervalent Bi Chains. J Am Chem Soc 2022; 144:9785-9796. [PMID: 35613438 DOI: 10.1021/jacs.2c02281] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Abstract
The link between crystal and electronic structure is crucial for understanding structure-property relations in solid-state chemistry. In particular, it has been instrumental in understanding topological materials, where electrons behave differently than they would in conventional solids. Herein, we identify 1D Bi chains as a structural motif of interest for topological materials. We focus on Sm3ZrBi5, a new quasi-one-dimensional (1D) compound in the Ln3MPn5 (Ln = lanthanide; M = metal; Pn = pnictide) family that crystallizes in the P63/mcm space group. Density functional theory calculations indicate a complex, topologically nontrivial electronic structure that changes significantly in the presence of spin-orbit coupling. Magnetic measurements show a quasi-1D antiferromagnetic structure with two magnetic transitions at 11.7 and 10.7 K that are invariant to applied field up to 9 T, indicating magnetically frustrated spins. Heat capacity, electrical, and thermoelectric measurements support this claim and suggest complex scattering behavior in Sm3ZrBi5. This work highlights 1D chains as an unexplored structural motif for identifying topological materials, as well as the potential for rich physical phenomena in the Ln3MPn5 family.
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Affiliation(s)
- Jason F Khoury
- Department of Chemistry, Princeton University, Princeton, New Jersey 08544, United States
| | - Bingzheng Han
- Department of Physics, Princeton University, Princeton, New Jersey 08544, United States
| | - Milena Jovanovic
- Department of Chemistry, Princeton University, Princeton, New Jersey 08544, United States
| | - Ratnadwip Singha
- Department of Chemistry, Princeton University, Princeton, New Jersey 08544, United States
| | - Xiaoyu Song
- Department of Chemistry, Princeton University, Princeton, New Jersey 08544, United States
| | - Raquel Queiroz
- Department of Physics, Columbia University, New York, New York 10027, United States
| | - Nai-Phuan Ong
- Department of Physics, Princeton University, Princeton, New Jersey 08544, United States
| | - Leslie M Schoop
- Department of Chemistry, Princeton University, Princeton, New Jersey 08544, United States
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