1
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Chen Z, Li R, Bai Y, Mao N, Zeer M, Go D, Dai Y, Huang B, Mokrousov Y, Niu C. Topology-Engineered Orbital Hall Effect in Two-Dimensional Ferromagnets. NANO LETTERS 2024. [PMID: 38619844 DOI: 10.1021/acs.nanolett.3c05129] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 04/16/2024]
Abstract
Recent advances in the manipulation of the orbital angular momentum (OAM) within the paradigm of orbitronics presents a promising avenue for the design of future electronic devices. In this context, the recently observed orbital Hall effect (OHE) occupies a special place. Here, focusing on both the second-order topological and quantum anomalous Hall insulators in two-dimensional ferromagnets, we demonstrate that topological phase transitions present an efficient and straightforward way to engineer the OHE, where the OAM distribution can be controlled by the nature of the band inversion. Using first-principles calculations, we identify Janus RuBrCl and three septuple layers of MnBi2Te4 as experimentally feasible examples of the proposed mechanism of OHE engineering by topology. With our work, we open up new possibilities for innovative applications in topological spintronics and orbitronics.
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Affiliation(s)
- Zhiqi Chen
- School of Physics, State Key Laboratory of Crystal Materials, Shandong University, Jinan 250100, China
| | - Runhan Li
- School of Physics, State Key Laboratory of Crystal Materials, Shandong University, Jinan 250100, China
| | - Yingxi Bai
- School of Physics, State Key Laboratory of Crystal Materials, Shandong University, Jinan 250100, China
| | - Ning Mao
- School of Physics, State Key Laboratory of Crystal Materials, Shandong University, Jinan 250100, China
| | - Mahmoud Zeer
- Peter Grünberg Institute, Forschungszentrum Jülich, 52425 Jülich, Germany
- Department of Physics, RWTH Aachen University, 52056 Aachen, Germany
| | - Dongwook Go
- Institute of Physics, Johannes Gutenberg University Mainz, 55099 Mainz, Germany
| | - Ying Dai
- School of Physics, State Key Laboratory of Crystal Materials, Shandong University, Jinan 250100, China
| | - Baibiao Huang
- School of Physics, State Key Laboratory of Crystal Materials, Shandong University, Jinan 250100, China
| | - Yuriy Mokrousov
- Institute of Physics, Johannes Gutenberg University Mainz, 55099 Mainz, Germany
| | - Chengwang Niu
- School of Physics, State Key Laboratory of Crystal Materials, Shandong University, Jinan 250100, China
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2
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Hu C, Qian T, Ni N. Recent progress in MnBi 2nTe 3n+1 intrinsic magnetic topological insulators: crystal growth, magnetism and chemical disorder. Natl Sci Rev 2024; 11:nwad282. [PMID: 38213523 PMCID: PMC10776370 DOI: 10.1093/nsr/nwad282] [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: 04/21/2023] [Revised: 08/19/2023] [Accepted: 09/06/2023] [Indexed: 01/13/2024] Open
Abstract
The search for magnetic topological materials has been at the forefront of condensed matter research for their potential to host exotic states such as axion insulators, magnetic Weyl semimetals, Chern insulators, etc. To date, the MnBi2nTe3n+1 family is the only group of materials showcasing van der Waals-layered structures, intrinsic magnetism and non-trivial band topology without trivial bands at the Fermi level. The interplay between magnetism and band topology in this family has led to the proposal of various topological phenomena, including the quantum anomalous Hall effect, quantum spin Hall effect and quantum magnetoelectric effect. Among these, the quantum anomalous Hall effect has been experimentally observed at record-high temperatures, highlighting the unprecedented potential of this family of materials in fundamental science and technological innovation. In this paper, we provide a comprehensive review of the research progress in this intrinsic magnetic topological insulator family, with a focus on single-crystal growth, characterization of chemical disorder, manipulation of magnetism through chemical substitution and external pressure, and important questions that remain to be conclusively answered.
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Affiliation(s)
- Chaowei Hu
- Department of Physics and Astronomy and California NanoSystems Institute, University of California-Los Angeles, Los Angeles, CA 90095, USA
| | - Tiema Qian
- Department of Physics and Astronomy and California NanoSystems Institute, University of California-Los Angeles, Los Angeles, CA 90095, USA
| | - Ni Ni
- Department of Physics and Astronomy and California NanoSystems Institute, University of California-Los Angeles, Los Angeles, CA 90095, USA
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3
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Jin KH, Jiang W, Sethi G, Liu F. Topological quantum devices: a review. NANOSCALE 2023; 15:12787-12817. [PMID: 37490310 DOI: 10.1039/d3nr01288c] [Citation(s) in RCA: 2] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 07/26/2023]
Abstract
The introduction of the concept of topology into condensed matter physics has greatly deepened our fundamental understanding of transport properties of electrons as well as all other forms of quasi particles in solid materials. It has also fostered a paradigm shift from conventional electronic/optoelectronic devices to novel quantum devices based on topology-enabled quantum device functionalities that transfer energy and information with unprecedented precision, robustness, and efficiency. In this article, the recent research progress in topological quantum devices is reviewed. We first outline the topological spintronic devices underlined by the spin-momentum locking property of topology. We then highlight the topological electronic devices based on quantized electron and dissipationless spin conductivity protected by topology. Finally, we discuss quantum optoelectronic devices with topology-redefined photoexcitation and emission. The field of topological quantum devices is only in its infancy, we envision many significant advances in the near future.
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Affiliation(s)
- Kyung-Hwan Jin
- Center for Artificial Low Dimensional Electronic Systems, Institute for Basic Science (IBS), Pohang 37673, Republic of Korea
| | - Wei Jiang
- School of Physics, Beijing Institute of Technology, Beijing 100081, China
| | - Gurjyot Sethi
- Department of Materials Science and Engineering, University of Utah, Salt Lake City, Utah 84112, USA.
| | - Feng Liu
- Department of Materials Science and Engineering, University of Utah, Salt Lake City, Utah 84112, USA.
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4
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Vakulenko A, Kiriushechkina S, Smirnova D, Guddala S, Komissarenko F, Alù A, Allen M, Allen J, Khanikaev AB. Adiabatic topological photonic interfaces. Nat Commun 2023; 14:4629. [PMID: 37532693 PMCID: PMC10397281 DOI: 10.1038/s41467-023-40238-5] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/22/2022] [Accepted: 07/19/2023] [Indexed: 08/04/2023] Open
Abstract
Topological phases of matter have been attracting significant attention across diverse fields, from inherently quantum systems to classical photonic and acoustic metamaterials. In photonics, topological phases offer resilience and bring novel opportunities to control light with pseudo-spins. However, topological photonic systems can suffer from limitations, such as breakdown of topological properties due to their symmetry-protected origin and radiative leakage. Here we introduce adiabatic topological photonic interfaces, which help to overcome these issues. We predict and experimentally confirm that topological metasurfaces with slowly varying synthetic gauge fields significantly improve the guiding features of spin-Hall and valley-Hall topological structures commonly used in the design of topological photonic devices. Adiabatic variation in the domain wall profiles leads to the delocalization of topological boundary modes, making them less sensitive to details of the lattice, perceiving the structure as an effectively homogeneous Dirac metasurface. As a result, the modes showcase improved bandgap crossing, longer radiative lifetimes and propagation distances.
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Affiliation(s)
- Anton Vakulenko
- Electrical Engineering and Physics, The City College of New York (USA), New York, NY, 10031, USA
| | - Svetlana Kiriushechkina
- Electrical Engineering and Physics, The City College of New York (USA), New York, NY, 10031, USA
| | - Daria Smirnova
- ARC Centre of Excellence for Transformative Meta-Optical Systems (TMOS), Research School of Physics, The Australian National University, Canberra, ACT, 2601, Australia
| | - Sriram Guddala
- Electrical Engineering and Physics, The City College of New York (USA), New York, NY, 10031, USA
| | - Filipp Komissarenko
- Electrical Engineering and Physics, The City College of New York (USA), New York, NY, 10031, USA
| | - Andrea Alù
- Electrical Engineering and Physics, The City College of New York (USA), New York, NY, 10031, USA
- Physics Program, Graduate Center of the City University of New York, New York, NY, 10016, USA
| | - Monica Allen
- Air Force Research Laboratory, Munitions Directorate, Eglin AFB, FL, USA
| | - Jeffery Allen
- Air Force Research Laboratory, Munitions Directorate, Eglin AFB, FL, USA
| | - Alexander B Khanikaev
- Electrical Engineering and Physics, The City College of New York (USA), New York, NY, 10031, USA.
- Physics Program, Graduate Center of the City University of New York, New York, NY, 10016, USA.
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5
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Mammadov FM, Niftiev NN, Jafarov YI, Babanly DM, Bakhtiyarly IB, Babanly MB. Physicochemical Analysis of the MnTе–Ga2Tе3–In2Tе3 System and AC Electrical Conductivity of MnGaInTe4. RUSS J INORG CHEM+ 2022. [DOI: 10.1134/s0036023622600769] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022]
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6
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Liang A, Chen C, Zheng H, Xia W, Huang K, Wei L, Yang H, Chen Y, Zhang X, Xu X, Wang M, Guo Y, Yang L, Liu Z, Chen Y. Approaching a Minimal Topological Electronic Structure in Antiferromagnetic Topological Insulator MnBi 2Te 4 via Surface Modification. NANO LETTERS 2022; 22:4307-4314. [PMID: 35604392 DOI: 10.1021/acs.nanolett.1c04930] [Citation(s) in RCA: 8] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/15/2023]
Abstract
The topological electronic structure plays a central role in the nontrivial physical properties in topological quantum materials. A minimal, "hydrogen-atom-like" topological electronic structure is desired for research. In this work, we demonstrate an effort toward the realization of such a system in the intrinsic magnetic topological insulator MnBi2Te4, by manipulating the topological surface state (TSS) via surface modification. Using high resolution laser- and synchrotron-based angle-resolved photoemission spectroscopy (ARPES), we found the TSS in MnBi2Te4 is heavily hybridized with a trivial Rashba-type surface state (RSS), which could be efficiently removed by the in situ surface potassium (K) dosing. By employing multiple experimental methods to characterize K dosed surface, we attribute such a modification to the electrochemical reactions of K clusters on the surface. Our work not only gives a clear band assignment in MnBi2Te4 but also provides possible new routes in accentuating the topological behavior in the magnetic topological quantum materials.
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Affiliation(s)
- Aiji Liang
- School of Physical Science and Technology, ShanghaiTech University, Shanghai 201210, China
- ShanghaiTech Laboratory for Topological Physics, Shanghai 200031, China
| | - Cheng Chen
- Clarendon Laboratory, Department of Physics, University of Oxford, Oxford OX1 3PU, U.K
| | - Huijun Zheng
- School of Physical Science and Technology, ShanghaiTech University, Shanghai 201210, China
| | - Wei Xia
- School of Physical Science and Technology, ShanghaiTech University, Shanghai 201210, China
- ShanghaiTech Laboratory for Topological Physics, Shanghai 200031, China
| | - Kui Huang
- School of Physical Science and Technology, ShanghaiTech University, Shanghai 201210, China
| | - Liyang Wei
- School of Physical Science and Technology, ShanghaiTech University, Shanghai 201210, China
| | - Haifeng Yang
- School of Physical Science and Technology, ShanghaiTech University, Shanghai 201210, China
| | - Yujie Chen
- State Key Laboratory of Low Dimensional Quantum Physics, Department of Physics, Tsinghua University, Beijing 100084, China
| | - Xin Zhang
- School of Physical Science and Technology, ShanghaiTech University, Shanghai 201210, China
| | - Xuguang Xu
- School of Physical Science and Technology, ShanghaiTech University, Shanghai 201210, China
- ShanghaiTech Laboratory for Topological Physics, Shanghai 200031, China
| | - Meixiao Wang
- School of Physical Science and Technology, ShanghaiTech University, Shanghai 201210, China
- ShanghaiTech Laboratory for Topological Physics, Shanghai 200031, China
| | - Yanfeng Guo
- School of Physical Science and Technology, ShanghaiTech University, Shanghai 201210, China
- ShanghaiTech Laboratory for Topological Physics, Shanghai 200031, China
| | - Lexian Yang
- State Key Laboratory of Low Dimensional Quantum Physics, Department of Physics, Tsinghua University, Beijing 100084, China
- Frontier Science Center for Quantum Information, Beijing 100084, China
| | - Zhongkai Liu
- School of Physical Science and Technology, ShanghaiTech University, Shanghai 201210, China
- ShanghaiTech Laboratory for Topological Physics, Shanghai 200031, China
| | - Yulin Chen
- School of Physical Science and Technology, ShanghaiTech University, Shanghai 201210, China
- ShanghaiTech Laboratory for Topological Physics, Shanghai 200031, China
- Clarendon Laboratory, Department of Physics, University of Oxford, Oxford OX1 3PU, U.K
- State Key Laboratory of Low Dimensional Quantum Physics, Department of Physics, Tsinghua University, Beijing 100084, China
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7
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Proximity-Induced Magnetism in a Topological Insulator/Half-Metallic Ferromagnetic Thin Film Heterostructure. COATINGS 2022. [DOI: 10.3390/coatings12060750] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/07/2022]
Abstract
Topological insulator (TI) Bi2Se3 thin films were prepared on half-metallic ferromagnetic La0.7Sr0.3MnO3 thin film by magnetron sputtering, forming a TI/FM heterostructure. The conductivity of Bi2Se3was modified by La0.7Sr0.3MnO3 at high- and low-temperature regions via different mechanisms, which could be explained by the short-range interactions and long-range interaction between ferromagnetic insulator and Bi2Se3 due to the proximity effect. Magnetic and transport measurements prove that the ferromagnetic phase and extra magnetic moment are induced in Bi2Se3 films. The weak anti-localized (WAL) effect was suppressed in Bi2Se3 films, accounting for the magnetism of La0.7Sr0.3MnO3 layers. This work clarifies the special behavior in Bi2Se3/La0.7Sr0.3MnO3 heterojunctions, which provides an effective way to study the magnetic proximity effect of the ferromagnetic phase in topological insulators.
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8
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He QL, Hughes TL, Armitage NP, Tokura Y, Wang KL. Topological spintronics and magnetoelectronics. NATURE MATERIALS 2022; 21:15-23. [PMID: 34949869 DOI: 10.1038/s41563-021-01138-5] [Citation(s) in RCA: 32] [Impact Index Per Article: 16.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 08/20/2020] [Accepted: 09/21/2021] [Indexed: 05/08/2023]
Abstract
Topological electronic materials, such as topological insulators, are distinct from trivial materials in the topology of their electronic band structures that lead to robust, unconventional topological states, which could bring revolutionary developments in electronics. This Perspective summarizes developments of topological insulators in various electronic applications including spintronics and magnetoelectronics. We group and analyse several important phenomena in spintronics using topological insulators, including spin-orbit torque, the magnetic proximity effect, interplay between antiferromagnetism and topology, and the formation of topological spin textures. We also outline recent developments in magnetoelectronics such as the axion insulator and the topological magnetoelectric effect observed using different topological insulators.
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Affiliation(s)
- Qing Lin He
- International Center for Quantum Materials, School of Physics, Peking University, Beijing, China.
- Collaborative Innovation Center of Quantum Matter, Beijing, China.
- Interdisciplinary Institute of Light-Element Quantum Materials and Research Center for Light-Element Advanced Materials, Peking University, Beijing, China.
| | - Taylor L Hughes
- Department of Physics and Institute for Condensed Matter Theory, University of Illinois at Urbana-Champaign, Urbana, IL, USA
| | - N Peter Armitage
- Department of Physics and Astronomy, The Johns Hopkins University, Baltimore, MD, USA
| | - Yoshinori Tokura
- RIKEN Center for Emergent Matter Science (CEMS), Wako, Japan
- Tokyo College, University of Tokyo, Tokyo, Japan
| | - Kang L Wang
- Department of Electrical and Computer Engineering, University of California, Los Angeles, CA, USA.
- Center of Quantum Sciences and Engineering, University of California, Los Angeles, CA, USA.
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9
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Bhattacharyya S, Akhgar G, Gebert M, Karel J, Edmonds MT, Fuhrer MS. Recent Progress in Proximity Coupling of Magnetism to Topological Insulators. ADVANCED MATERIALS (DEERFIELD BEACH, FLA.) 2021; 33:e2007795. [PMID: 34185344 DOI: 10.1002/adma.202007795] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 11/16/2020] [Revised: 01/11/2021] [Indexed: 05/08/2023]
Abstract
Inducing long-range magnetic order in 3D topological insulators can gap the Dirac-like metallic surface states, leading to exotic new phases such as the quantum anomalous Hall effect or the axion insulator state. These magnetic topological phases can host robust, dissipationless charge and spin currents or unique magnetoelectric behavior, which can be exploited in low-energy electronics and spintronics applications. Although several different strategies have been successfully implemented to realize these states, to date these phenomena have been confined to temperatures below a few Kelvin. This review focuses on one strategy: inducing magnetic order in topological insulators by proximity of magnetic materials, which has the capability for room temperature operation, unlocking the potential of magnetic topological phases for applications. The unique advantages of this strategy, the important physical mechanisms facilitating magnetic proximity effect, and the recent progress to achieve, understand, and harness proximity-coupled magnetic order in topological insulators are discussed. Some emerging new phenomena and applications enabled by proximity coupling of magnetism and topological materials, such as skyrmions and the topological Hall effect, are also highlighted, and the authors conclude with an outlook on remaining challenges and opportunities in the field.
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Affiliation(s)
- Semonti Bhattacharyya
- School of Physics and Astronomy, Monash University, Victoria, 3800, Australia
- ARC Centre of Excellence in Future Low-Energy Electronics Technologies, Monash University, Victoria, 3800, Australia
| | - Golrokh Akhgar
- School of Physics and Astronomy, Monash University, Victoria, 3800, Australia
- ARC Centre of Excellence in Future Low-Energy Electronics Technologies, Monash University, Victoria, 3800, Australia
| | - Matthew Gebert
- School of Physics and Astronomy, Monash University, Victoria, 3800, Australia
- ARC Centre of Excellence in Future Low-Energy Electronics Technologies, Monash University, Victoria, 3800, Australia
| | - Julie Karel
- ARC Centre of Excellence in Future Low-Energy Electronics Technologies, Monash University, Victoria, 3800, Australia
- Department of Materials Science and Engineering, Monash University, Clayton, Victoria, 3800, Australia
| | - Mark T Edmonds
- School of Physics and Astronomy, Monash University, Victoria, 3800, Australia
- ARC Centre of Excellence in Future Low-Energy Electronics Technologies, Monash University, Victoria, 3800, Australia
| | - Michael S Fuhrer
- School of Physics and Astronomy, Monash University, Victoria, 3800, Australia
- ARC Centre of Excellence in Future Low-Energy Electronics Technologies, Monash University, Victoria, 3800, Australia
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10
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Eremeev SV, Rusinov IP, Koroteev YM, Vyazovskaya AY, Hoffmann M, Echenique PM, Ernst A, Otrokov MM, Chulkov EV. Topological Magnetic Materials of the (MnSb 2Te 4)·(Sb 2Te 3) n van der Waals Compounds Family. J Phys Chem Lett 2021; 12:4268-4277. [PMID: 33908787 DOI: 10.1021/acs.jpclett.1c00875] [Citation(s) in RCA: 12] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 06/12/2023]
Abstract
Using density functional theory, we propose the (MnSb2Te4)·(Sb2Te3)n family of stoichiometric van der Waals compounds that harbor multiple topologically nontrivial magnetic phases. In the ground state, the first three members of the family (n = 0, 1, 2) are 3D antiferromagnetic topological insulators, while for n ≥ 3 a special phase is formed, in which a nontrivial topological order coexists with a partial magnetic disorder in the system of the decoupled 2D ferromagnets, whose magnetizations point randomly along the third direction. Furthermore, due to a weak interlayer exchange coupling, these materials can be field-driven into the FM Weyl semimetal (n = 0) or FM axion insulator states (n ≥ 1). Finally, in two dimensions, we reveal these systems to show intrinsic quantum anomalous Hall and AFM axion insulator states, as well as quantum Hall state, achieved under external magnetic field. Our results demonstrate that MnSb2Te4 is not topologically trivial as was previously believed that opens possibilities of realization of a wealth of topologically nontrivial states in the (MnSb2Te4)·(Sb2Te3)n family.
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Affiliation(s)
- S V Eremeev
- Institute of Strength Physics and Materials Science, Russian Academy of Sciences, 634021 Tomsk, Russia
- Tomsk State University, 634050 Tomsk, Russia
| | - I P Rusinov
- Tomsk State University, 634050 Tomsk, Russia
- Saint Petersburg State University, 198504 Saint Petersburg, Russia
| | - Yu M Koroteev
- Institute of Strength Physics and Materials Science, Russian Academy of Sciences, 634021 Tomsk, Russia
| | - A Yu Vyazovskaya
- Tomsk State University, 634050 Tomsk, Russia
- Saint Petersburg State University, 198504 Saint Petersburg, Russia
| | - M Hoffmann
- Institut für Theoretische Physik, Johannes Kepler Universität, A 4040 Linz, Austria
| | - P M Echenique
- Centro de Física de Materiales (CFM-MPC), Centro Mixto CSIC-UPV/EHU, 20018 Donostia-San Sebastián, Basque Country, Spain
- Departamento de Física de Materiales UPV/EHU, 20080 Donostia-San Sebastián, Basque Country, Spain
- Donostia International Physics Center (DIPC), 20018 Donostia-San Sebastián, Basque Country, Spain
| | - A Ernst
- Institut für Theoretische Physik, Johannes Kepler Universität, A 4040 Linz, Austria
- Max-Planck-Institut für Mikrostrukturphysik, Weinberg 2, D-06120 Halle, Germany
| | - M M Otrokov
- Centro de Física de Materiales (CFM-MPC), Centro Mixto CSIC-UPV/EHU, 20018 Donostia-San Sebastián, Basque Country, Spain
- IKERBASQUE, Basque Foundation for Science, 48011, Bilbao, Spain
| | - E V Chulkov
- Saint Petersburg State University, 198504 Saint Petersburg, Russia
- Centro de Física de Materiales (CFM-MPC), Centro Mixto CSIC-UPV/EHU, 20018 Donostia-San Sebastián, Basque Country, Spain
- Departamento de Física de Materiales UPV/EHU, 20080 Donostia-San Sebastián, Basque Country, Spain
- Donostia International Physics Center (DIPC), 20018 Donostia-San Sebastián, Basque Country, Spain
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11
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Figueroa AI, Bonell F, Cuxart MG, Valvidares M, Gargiani P, van der Laan G, Mugarza A, Valenzuela SO. Absence of Magnetic Proximity Effect at the Interface of Bi_{2}Se_{3} and (Bi,Sb)_{2}Te_{3} with EuS. PHYSICAL REVIEW LETTERS 2020; 125:226801. [PMID: 33315425 DOI: 10.1103/physrevlett.125.226801] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 10/21/2019] [Revised: 09/02/2020] [Accepted: 10/16/2020] [Indexed: 06/12/2023]
Abstract
We performed x-ray magnetic circular dichroism (XMCD) measurements on heterostructures comprising topological insulators (TIs) of the (Bi,Sb)_{2}(Se,Te)_{3} family and the magnetic insulator EuS. XMCD measurements allow us to investigate element-selective magnetic proximity effects at the very TI/EuS interface. A systematic analysis reveals that there is neither significant induced magnetism within the TI nor an enhancement of the Eu magnetic moment at such interface. The induced magnetic moments in Bi, Sb, Te, and Se sites are lower than the estimated detection limit of the XMCD measurements of ∼10^{-3} μ_{B}/at.
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Affiliation(s)
- A I Figueroa
- Catalan Institute of Nanoscience and Nanotechnology (ICN2), CSIC and BIST, Campus UAB, Bellaterra, 08193 Barcelona, Spain
| | - F Bonell
- Catalan Institute of Nanoscience and Nanotechnology (ICN2), CSIC and BIST, Campus UAB, Bellaterra, 08193 Barcelona, Spain
| | - M G Cuxart
- Catalan Institute of Nanoscience and Nanotechnology (ICN2), CSIC and BIST, Campus UAB, Bellaterra, 08193 Barcelona, Spain
- Universitat Autònoma de Barcelona (UAB), Bellaterra 08193, Spain
| | - M Valvidares
- ALBA Synchrotron Light Source, Barcelona 08290, Spain
| | - P Gargiani
- ALBA Synchrotron Light Source, Barcelona 08290, Spain
| | - G van der Laan
- Diamond Light Source, Harwell Science and Innovation Campus, Didcot OX11 0DE, United Kingdom
| | - A Mugarza
- Catalan Institute of Nanoscience and Nanotechnology (ICN2), CSIC and BIST, Campus UAB, Bellaterra, 08193 Barcelona, Spain
- Institució Catalana de Recerca i Estudis Avançats (ICREA), Barcelona 08010, Spain
| | - S O Valenzuela
- Catalan Institute of Nanoscience and Nanotechnology (ICN2), CSIC and BIST, Campus UAB, Bellaterra, 08193 Barcelona, Spain
- Institució Catalana de Recerca i Estudis Avançats (ICREA), Barcelona 08010, Spain
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12
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Lei C, Chen S, MacDonald AH. Magnetized topological insulator multilayers. Proc Natl Acad Sci U S A 2020; 117:27224-27230. [PMID: 33077591 PMCID: PMC7959519 DOI: 10.1073/pnas.2014004117] [Citation(s) in RCA: 27] [Impact Index Per Article: 6.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/18/2022] Open
Abstract
We discuss the magnetic and topological properties of bulk crystals and quasi-two-dimensional (quasi-2D) thin films formed by stacking intrinsic magnetized topological insulator (for example, Mn ([Formula: see text])2X4 with X = Se,Te) septuple layers and topological insulator quintuple layers in arbitrary order. Our analysis makes use of a simplified model that retains only Dirac cone degrees of freedom on both surfaces of each septuple or quintuple layer. We demonstrate the model's applicability and estimate its parameters by comparing with ab initio density-functional theory (DFT) calculations. We then employ the coupled Dirac cone model to provide an explanation for the dependence of thin-film properties, particularly the presence or absence of the quantum anomalous Hall effect, on film thickness, magnetic configuration, and stacking arrangement, and to comment on the design of Weyl superlattices.
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Affiliation(s)
- Chao Lei
- Department of Physics, The University of Texas at Austin, Austin, TX 78712
| | - Shu Chen
- Department of Physics, The University of Texas at Austin, Austin, TX 78712
- Department of Physics, Shanghai University, Shanghai 200444, China
| | - Allan H MacDonald
- Department of Physics, The University of Texas at Austin, Austin, TX 78712;
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13
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Menshchikova TV, Eremeev SV, Kuznetsov VM, Chulkov EV. Interplay of Topological States on TI/TCI Interfaces. MATERIALS (BASEL, SWITZERLAND) 2020; 13:E4481. [PMID: 33050359 PMCID: PMC7601830 DOI: 10.3390/ma13204481] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 07/31/2020] [Revised: 09/18/2020] [Accepted: 09/24/2020] [Indexed: 11/17/2022]
Abstract
Based on first-principles calculations, we study electronic structure of interfaces between a Z2 topological insulator (TI) SnBi2Te4 and a topological crystalline insulator (TCI) SnTe. We consider two interface models characterized by the different atomic structure on the contact of the SnTe(111) and SnBi2Te4(0001) slabs: the model when two materials are connected without intermixing (abrupt type of interface) and the interface model predicted to be realized at epitaxial immersion growth on topological insulator substrates (smooth interface). We find that a strong potential gradient at the abrupt interface leads to the redistribution of the topological states deeper from the interface plane which prevents the annihilation of the Γ¯ Dirac states, predicted earlier. In contrast, a smooth interface is characterized by minor charge transfer, which promotes the strong interplay between TI and TCI Γ¯ Dirac cones leading to their complete annihilation.The M¯ topologically protected Dirac state of SnTe(111) survives irrespective of the interface structure.
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Affiliation(s)
- Tatiana V. Menshchikova
- Laboratory of Nanostructured Surfaces and Coatings, Tomsk State University, 634050 Tomsk, Russia;
| | - Sergey V. Eremeev
- Laboratory Surface Phenomena Physics, Institute of Strength Physics and Materials Science, Siberian Branch of Russian Academy of Sciences, 634055 Tomsk, Russia;
| | - Vladimir M. Kuznetsov
- Laboratory of Nanostructured Surfaces and Coatings, Tomsk State University, 634050 Tomsk, Russia;
| | - Evgueni V. Chulkov
- Laboratory of Electronic and Spin Structure of Nanosystems, Saint Petersburg State University, 198504 Saint Petersburg, Russia;
- Donostia International Physics Center (DIPC), 20018 San Sebastián/Donostia, Spain
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14
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Fabrication of a novel magnetic topological heterostructure and temperature evolution of its massive Dirac cone. Nat Commun 2020; 11:4821. [PMID: 32973165 PMCID: PMC7515900 DOI: 10.1038/s41467-020-18645-9] [Citation(s) in RCA: 14] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/29/2020] [Accepted: 09/06/2020] [Indexed: 11/12/2022] Open
Abstract
Materials that possess nontrivial topology and magnetism is known to exhibit exotic quantum phenomena such as the quantum anomalous Hall effect. Here, we fabricate a novel magnetic topological heterostructure Mn4Bi2Te7/Bi2Te3 where multiple magnetic layers are inserted into the topmost quintuple layer of the original topological insulator Bi2Te3. A massive Dirac cone (DC) with a gap of 40–75 meV at 16 K is observed. By tracing the temperature evolution, this gap is shown to gradually decrease with increasing temperature and a blunt transition from a massive to a massless DC occurs around 200–250 K. Structural analysis shows that the samples also contain MnBi2Te4/Bi2Te3. Magnetic measurements show that there are two distinct Mn components in the system that corresponds to the two heterostructures; MnBi2Te4/Bi2Te3 is paramagnetic at 6 K while Mn4Bi2Te7/Bi2Te3 is ferromagnetic with a negative hysteresis (critical temperature ~20 K). This novel heterostructure is potentially important for future device applications. Magnetic topological heterostructures are promising devices to manipulate emergent quantum effects. Here, Hirahara et al. fabricate a novel magnetic topological heterostructure with a massive Dirac cone which becomes a massless one tuned by temperature.
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15
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Shikin AM, Estyunin DA, Klimovskikh II, Filnov SO, Schwier EF, Kumar S, Miyamoto K, Okuda T, Kimura A, Kuroda K, Yaji K, Shin S, Takeda Y, Saitoh Y, Aliev ZS, Mamedov NT, Amiraslanov IR, Babanly MB, Otrokov MM, Eremeev SV, Chulkov EV. Nature of the Dirac gap modulation and surface magnetic interaction in axion antiferromagnetic topological insulator [Formula: see text]. Sci Rep 2020; 10:13226. [PMID: 32764583 PMCID: PMC7413556 DOI: 10.1038/s41598-020-70089-9] [Citation(s) in RCA: 19] [Impact Index Per Article: 4.8] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/03/2020] [Accepted: 07/22/2020] [Indexed: 11/09/2022] Open
Abstract
Modification of the gap at the Dirac point (DP) in axion antiferromagnetic topological insulator [Formula: see text] and its electronic and spin structure have been studied by angle- and spin-resolved photoemission spectroscopy (ARPES) under laser excitation at various temperatures (9-35 K), light polarizations and photon energies. We have distinguished both large (60-70 meV) and reduced ([Formula: see text]) gaps at the DP in the ARPES dispersions, which remain open above the Neél temperature ([Formula: see text]). We propose that the gap above [Formula: see text] remains open due to a short-range magnetic field generated by chiral spin fluctuations. Spin-resolved ARPES, XMCD and circular dichroism ARPES measurements show a surface ferromagnetic ordering for the "large gap" sample and apparently significantly reduced effective magnetic moment for the "reduced gap" sample. These observations can be explained by a shift of the Dirac cone (DC) state localization towards the second Mn layer due to structural disturbance and surface relaxation effects, where DC state is influenced by compensated opposite magnetic moments. As we have shown by means of ab-initio calculations surface structural modification can result in a significant modulation of the DP gap.
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Affiliation(s)
- A. M. Shikin
- Saint Petersburg State University, 198504 Saint Petersburg, Russia
| | - D. A. Estyunin
- Saint Petersburg State University, 198504 Saint Petersburg, Russia
| | | | - S. O. Filnov
- Saint Petersburg State University, 198504 Saint Petersburg, Russia
| | - E. F. Schwier
- Hiroshima Synchrotron Radiation Center, Hiroshima University, Hiroshima, Japan
| | - S. Kumar
- Hiroshima Synchrotron Radiation Center, Hiroshima University, Hiroshima, Japan
| | - K. Miyamoto
- Hiroshima Synchrotron Radiation Center, Hiroshima University, Hiroshima, Japan
| | - T. Okuda
- Hiroshima Synchrotron Radiation Center, Hiroshima University, Hiroshima, Japan
| | - A. Kimura
- Department of Physical Sciences, Graduate School of Science, Hiroshima University, Hiroshima, Japan
| | - K. Kuroda
- ISSP, University of Tokyo, Kashiwa, Chiba 277-8581 Japan
| | - K. Yaji
- ISSP, University of Tokyo, Kashiwa, Chiba 277-8581 Japan
| | - S. Shin
- ISSP, University of Tokyo, Kashiwa, Chiba 277-8581 Japan
| | - Y. Takeda
- Materials Sciences Research Center, Japan Atomic Energy Agency, Sayo, Hyogo 679-5148 Japan
| | - Y. Saitoh
- Materials Sciences Research Center, Japan Atomic Energy Agency, Sayo, Hyogo 679-5148 Japan
| | - Z. S. Aliev
- Azerbaijan State Oil and Industry University, AZ1010 Baku, Azerbaijan
- Institute of Physics, ANAS, AZ1143 Baku, Azerbaijan
| | | | - I. R. Amiraslanov
- Institute of Physics, ANAS, AZ1143 Baku, Azerbaijan
- Baku State University, AZ1148 Baku, Azerbaijan
| | - M. B. Babanly
- Baku State University, AZ1148 Baku, Azerbaijan
- Institute of Catalysis and Inorganic Chemistry, ANAS, AZ1143 Baku, Azerbaijan
| | - M. M. Otrokov
- Centro de Física de Materiales (CFM-MPC), Centro Mixto CSIC-UPV/EHU, 20018 Donostia-San Sebastián, Basque Country Spain
- IKERBASQUE, Basque Foundation for Science, 48011 Bilbao, Basque Country Spain
| | - S. V. Eremeev
- Saint Petersburg State University, 198504 Saint Petersburg, Russia
- Institute of Strength Physics and Materials Science, 634055 Tomsk, Russia
- Tomsk State University, 634050 Tomsk, Russia
| | - E. V. Chulkov
- Saint Petersburg State University, 198504 Saint Petersburg, Russia
- Tomsk State University, 634050 Tomsk, Russia
- Donostia International Physics Center (DIPC), 20018 Donostia-San Sebastián, Basque Country Spain
- Departamento de Física de Materiales, Facultad de Ciencias Químicas, UPV/EHU, Apdo. 1072, 20080 San Sebastián, Spain
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16
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Abstract
In this contribution to the MDPI Condensed Matter issue in Honor of Nobel Laureate Professor K.A. Müller I review recent experimental progress on magnetism of semiconducting transition metal dichalcogenides (TMDs) from the local-magnetic probe point of view such as muon-spin rotation and discuss prospects for the creation of unique new device concepts with these materials. TMDs are the prominent class of layered materials, that exhibit a vast range of interesting properties including unconventional semiconducting, optical, and transport behavior originating from valley splitting. Until recently, this family has been missing one crucial member: magnetic semiconductor. The situation has changed over the past few years with the discovery of layered semiconducting magnetic crystals, for example CrI 3 and VI 2 . We have also very recently discovered unconventional magnetism in semiconducting Mo-based TMD systems 2H-MoTe 2 and 2H-MoSe 2 [Guguchia et. al., Science Advances 2018, 4(12)]. Moreover, we also show the evidence for the involvement of magnetism in semiconducting tungsten diselenide 2H-WSe 2 . These results open a path to studying the interplay of 2D physics, semiconducting properties and magnetism in TMDs. It also opens up a host of new opportunities to obtain tunable magnetic semiconductors, forming the basis for spintronics.
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17
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Prediction and observation of an antiferromagnetic topological insulator. Nature 2019; 576:416-422. [PMID: 31853084 DOI: 10.1038/s41586-019-1840-9] [Citation(s) in RCA: 222] [Impact Index Per Article: 44.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/20/2018] [Accepted: 09/18/2019] [Indexed: 11/08/2022]
Abstract
Magnetic topological insulators are narrow-gap semiconductor materials that combine non-trivial band topology and magnetic order1. Unlike their nonmagnetic counterparts, magnetic topological insulators may have some of the surfaces gapped, which enables a number of exotic phenomena that have potential applications in spintronics1, such as the quantum anomalous Hall effect2 and chiral Majorana fermions3. So far, magnetic topological insulators have only been created by means of doping nonmagnetic topological insulators with 3d transition-metal elements; however, such an approach leads to strongly inhomogeneous magnetic4 and electronic5 properties of these materials, restricting the observation of important effects to very low temperatures2,3. An intrinsic magnetic topological insulator-a stoichiometric well ordered magnetic compound-could be an ideal solution to these problems, but no such material has been observed so far. Here we predict by ab initio calculations and further confirm using various experimental techniques the realization of an antiferromagnetic topological insulator in the layered van der Waals compound MnBi2Te4. The antiferromagnetic ordering that MnBi2Te4 shows makes it invariant with respect to the combination of the time-reversal and primitive-lattice translation symmetries, giving rise to a ℤ2 topological classification; ℤ2 = 1 for MnBi2Te4, confirming its topologically nontrivial nature. Our experiments indicate that the symmetry-breaking (0001) surface of MnBi2Te4 exhibits a large bandgap in the topological surface state. We expect this property to eventually enable the observation of a number of fundamental phenomena, among them quantized magnetoelectric coupling6-8 and axion electrodynamics9,10. Other exotic phenomena could become accessible at much higher temperatures than those reached so far, such as the quantum anomalous Hall effect2 and chiral Majorana fermions3.
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18
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Otrokov MM, Rusinov IP, Blanco-Rey M, Hoffmann M, Vyazovskaya AY, Eremeev SV, Ernst A, Echenique PM, Arnau A, Chulkov EV. Unique Thickness-Dependent Properties of the van der Waals Interlayer Antiferromagnet MnBi_{2}Te_{4} Films. PHYSICAL REVIEW LETTERS 2019; 122:107202. [PMID: 30932645 DOI: 10.1103/physrevlett.122.107202] [Citation(s) in RCA: 142] [Impact Index Per Article: 28.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 10/11/2018] [Indexed: 06/09/2023]
Abstract
Using density functional theory and Monte Carlo calculations, we study the thickness dependence of the magnetic and electronic properties of a van der Waals interlayer antiferromagnet in the two-dimensional limit. Considering MnBi_{2}Te_{4} as a model material, we find it to demonstrate a remarkable set of thickness-dependent magnetic and topological transitions. While a single septuple layer block of MnBi_{2}Te_{4} is a topologically trivial ferromagnet, the thicker films made of an odd (even) number of blocks are uncompensated (compensated) interlayer antiferromagnets, which show wide band gap quantum anomalous Hall (zero plateau quantum anomalous Hall) states. Thus, MnBi_{2}Te_{4} is the first stoichiometric material predicted to realize the zero plateau quantum anomalous Hall state intrinsically. This state has been theoretically shown to host the exotic axion insulator phase.
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Affiliation(s)
- M M Otrokov
- Centro de Física de Materiales (CFM-MPC), Centro Mixto CSIC-UPV/EHU, 20018 Donostia-San Sebastián, Basque Country, Spain
- IKERBASQUE, Basque Foundation for Science, 48011 Bilbao, Spain
- Donostia International Physics Center (DIPC), 20018 Donostia-San Sebastián, Basque Country, Spain
- Saint Petersburg State University, 198504 Saint Petersburg, Russia
| | - I P Rusinov
- Saint Petersburg State University, 198504 Saint Petersburg, Russia
- Tomsk State University, 634050 Tomsk, Russia
| | - M Blanco-Rey
- Donostia International Physics Center (DIPC), 20018 Donostia-San Sebastián, Basque Country, Spain
- Departamento de Física de Materiales UPV/EHU, 20080 Donostia-San Sebastián, Basque Country, Spain
| | - M Hoffmann
- Institut für Theoretische Physik, Johannes Kepler Universität, A 4040 Linz, Austria
| | - A Yu Vyazovskaya
- Saint Petersburg State University, 198504 Saint Petersburg, Russia
- Tomsk State University, 634050 Tomsk, Russia
| | - S V Eremeev
- Saint Petersburg State University, 198504 Saint Petersburg, Russia
- Tomsk State University, 634050 Tomsk, Russia
- Institute of Strength Physics and Materials Science, Russian Academy of Sciences, 634021 Tomsk, Russia
| | - A Ernst
- Institut für Theoretische Physik, Johannes Kepler Universität, A 4040 Linz, Austria
- Max-Planck-Institut für Mikrostrukturphysik, Weinberg 2, D-06120 Halle, Germany
| | - P M Echenique
- Centro de Física de Materiales (CFM-MPC), Centro Mixto CSIC-UPV/EHU, 20018 Donostia-San Sebastián, Basque Country, Spain
- Donostia International Physics Center (DIPC), 20018 Donostia-San Sebastián, Basque Country, Spain
- Departamento de Física de Materiales UPV/EHU, 20080 Donostia-San Sebastián, Basque Country, Spain
| | - A Arnau
- Centro de Física de Materiales (CFM-MPC), Centro Mixto CSIC-UPV/EHU, 20018 Donostia-San Sebastián, Basque Country, Spain
- Donostia International Physics Center (DIPC), 20018 Donostia-San Sebastián, Basque Country, Spain
- Departamento de Física de Materiales UPV/EHU, 20080 Donostia-San Sebastián, Basque Country, Spain
| | - E V Chulkov
- Centro de Física de Materiales (CFM-MPC), Centro Mixto CSIC-UPV/EHU, 20018 Donostia-San Sebastián, Basque Country, Spain
- Donostia International Physics Center (DIPC), 20018 Donostia-San Sebastián, Basque Country, Spain
- Saint Petersburg State University, 198504 Saint Petersburg, Russia
- Departamento de Física de Materiales UPV/EHU, 20080 Donostia-San Sebastián, Basque Country, Spain
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