1
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Shi G, Wang F, Liu Y, Li Z, Tan HR, Yang D, Soumyanarayanan A, Yang H. Field-Free Manipulation of Two-Dimensional Ferromagnet CrTe 2 by Spin-Orbit Torques. NANO LETTERS 2024. [PMID: 38856112 DOI: 10.1021/acs.nanolett.4c01366] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/11/2024]
Abstract
Electrical manipulation of magnetic states in two-dimensional ferromagnetic systems is crucial in information storage and low-dimensional spintronics. Spin-orbit torque presents a rapid and energy-efficient method for electrical control of the magnetization. In this letter, we demonstrate a wafer-scale spin-orbit torque switching of two-dimensional ferromagnetic states. Using molecular beam epitaxy, we fabricate two-dimensional heterostructures composed of low crystal-symmetry WTe2 and ferromagnet CrTe2 with perpendicular anisotropy. By utilizing out-of-plane spins generated from WTe2, we achieve field-free switching of the CrTe2 perpendicular magnetization. The threshold switching current density in CrTe2/WTe2 is 1.2 × 106 A/cm2, 20 times smaller than that of the CrTe2/Pt control sample even with an external magnetic field. In addition, the switching behavior can be modulated by external magnetic fields and crystal symmetry. Our findings demonstrate a controllable and all-electric manipulation of perpendicular magnetization in a two-dimensional ferromagnet, representing a significant advancement toward the practical implementation of low-dimensional spintronic devices.
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Affiliation(s)
- Guoyi Shi
- Department of Electrical and Computer Engineering, National University of Singapore, Singapore 117576, Singapore
| | - Fei Wang
- Key Laboratory of Magnetic Molecules and Magnetic Information, Materials of Ministry of Education, School of Chemistry and Materials Science, Shanxi Normal University, Taiyuan 030006, China
| | - Yakun Liu
- Department of Electrical and Computer Engineering, National University of Singapore, Singapore 117576, Singapore
| | - Zhaohui Li
- Department of Electrical and Computer Engineering, National University of Singapore, Singapore 117576, Singapore
| | - Hui Ru Tan
- Institute of Materials Research & Engineering, Agency for Science, Technology & Research (A*STAR), Singapore 138634, Singapore
| | - Dongsheng Yang
- Department of Electrical and Computer Engineering, National University of Singapore, Singapore 117576, Singapore
| | - Anjan Soumyanarayanan
- Institute of Materials Research & Engineering, Agency for Science, Technology & Research (A*STAR), Singapore 138634, Singapore
- Department of Physics, National University of Singapore, Singapore 117551, Singapore
| | - Hyunsoo Yang
- Department of Electrical and Computer Engineering, National University of Singapore, Singapore 117576, Singapore
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2
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Li C, Wang R, Zhang S, Qin Y, Ying Z, Wei B, Dai Z, Guo F, Chen W, Zhang R, Wang B, Wang X, Song F. Observation of giant non-reciprocal charge transport from quantum Hall states in a topological insulator. NATURE MATERIALS 2024:10.1038/s41563-024-01874-4. [PMID: 38641696 DOI: 10.1038/s41563-024-01874-4] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/04/2023] [Accepted: 03/19/2024] [Indexed: 04/21/2024]
Abstract
Symmetry breaking in quantum materials is of great importance and can lead to non-reciprocal charge transport. Topological insulators provide a unique platform to study non-reciprocal charge transport due to their surface states, especially quantum Hall states under an external magnetic field. Here we report the observation of non-reciprocal charge transport mediated by quantum Hall states in devices composed of the intrinsic topological insulator Sn-Bi1.1Sb0.9Te2S, which is attributed to asymmetric scattering between quantum Hall states and Dirac surface states. A giant non-reciprocal coefficient of up to 2.26 × 105 A-1 is found. Our work not only reveals the properties of non-reciprocal charge transport of quantum Hall states in topological insulators but also paves the way for future electronic devices.
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Affiliation(s)
- Chunfeng Li
- National Laboratory of Solid State Microstructures, Collaborative Innovation Center of Advanced Microstructures, and School of Physics, Nanjing University, Nanjing, China
- Jiangsu Provincial Key Laboratory of Advanced Photonic and Electronic Materials, State Key Laboratory of Spintronics Devices and Technologies, School of Electronic Science and Engineering, Collaborative Innovation Center of Advanced Microstructures, Nanjing University, Nanjing, China
| | - Rui Wang
- National Laboratory of Solid State Microstructures, Collaborative Innovation Center of Advanced Microstructures, and School of Physics, Nanjing University, Nanjing, China
- Hefei National Laboratory, Hefei, China
| | - Shuai Zhang
- National Laboratory of Solid State Microstructures, Collaborative Innovation Center of Advanced Microstructures, and School of Physics, Nanjing University, Nanjing, China.
| | - Yuyuan Qin
- National Laboratory of Solid State Microstructures, Collaborative Innovation Center of Advanced Microstructures, and School of Physics, Nanjing University, Nanjing, China
| | - Zhe Ying
- National Laboratory of Solid State Microstructures, Collaborative Innovation Center of Advanced Microstructures, and School of Physics, Nanjing University, Nanjing, China
| | - Boyuan Wei
- National Laboratory of Solid State Microstructures, Collaborative Innovation Center of Advanced Microstructures, and School of Physics, Nanjing University, Nanjing, China
| | - Zheng Dai
- National Laboratory of Solid State Microstructures, Collaborative Innovation Center of Advanced Microstructures, and School of Physics, Nanjing University, Nanjing, China
| | - Fengyi Guo
- National Laboratory of Solid State Microstructures, Collaborative Innovation Center of Advanced Microstructures, and School of Physics, Nanjing University, Nanjing, China
| | - Wei Chen
- National Laboratory of Solid State Microstructures, Collaborative Innovation Center of Advanced Microstructures, and School of Physics, Nanjing University, Nanjing, China
| | - Rong Zhang
- Jiangsu Provincial Key Laboratory of Advanced Photonic and Electronic Materials, State Key Laboratory of Spintronics Devices and Technologies, School of Electronic Science and Engineering, Collaborative Innovation Center of Advanced Microstructures, Nanjing University, Nanjing, China
- Department of Physics, Xiamen University, Xiamen, China
| | - Baigeng Wang
- National Laboratory of Solid State Microstructures, Collaborative Innovation Center of Advanced Microstructures, and School of Physics, Nanjing University, Nanjing, China
| | - Xuefeng Wang
- Jiangsu Provincial Key Laboratory of Advanced Photonic and Electronic Materials, State Key Laboratory of Spintronics Devices and Technologies, School of Electronic Science and Engineering, Collaborative Innovation Center of Advanced Microstructures, Nanjing University, Nanjing, China.
| | - Fengqi Song
- National Laboratory of Solid State Microstructures, Collaborative Innovation Center of Advanced Microstructures, and School of Physics, Nanjing University, Nanjing, China.
- Institute of Atom Manufacturing, Nanjing University, Suzhou, China.
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3
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Tuvia G, Burshtein A, Silber I, Aharony A, Entin-Wohlman O, Goldstein M, Dagan Y. Enhanced Nonlinear Response by Manipulating the Dirac Point at the (111) LaTiO_{3}/SrTiO_{3} Interface. PHYSICAL REVIEW LETTERS 2024; 132:146301. [PMID: 38640380 DOI: 10.1103/physrevlett.132.146301] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 08/23/2023] [Accepted: 03/01/2024] [Indexed: 04/21/2024]
Abstract
Tunable spin-orbit interaction (SOI) is an important feature for future spin-based devices. In the presence of a magnetic field, SOI induces an asymmetry in the energy bands, which can produce nonlinear transport effects (V∼I^{2}). Here, we focus on such effects to study the role of SOI in the (111) LaTiO_{3}/SrTiO_{3} interface. This system is a convenient platform for understanding the role of SOI since it exhibits a single-band Hall response through the entire gate-voltage range studied. We report a pronounced rise in the nonlinear longitudinal resistance at a critical in-plane field H_{cr}. This rise disappears when a small out-of-plane field component is present. We explain these results by considering the location of the Dirac point formed at the crossing of the spin-split energy bands. An in-plane magnetic field pushes this point outside of the Fermi contour, and consequently changes the symmetry of the Fermi contours and intensifies the nonlinear transport. An out-of-plane magnetic field opens a gap at the Dirac point, thereby significantly diminishing the nonlinear effects. We propose that magnetoresistance effects previously reported in interfaces with SOI could be comprehended within our suggested scenario.
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Affiliation(s)
- G Tuvia
- School of Physics and Astronomy, Tel-Aviv University, Tel Aviv 6997801, Israel
| | - A Burshtein
- School of Physics and Astronomy, Tel-Aviv University, Tel Aviv 6997801, Israel
| | - I Silber
- School of Physics and Astronomy, Tel-Aviv University, Tel Aviv 6997801, Israel
| | - A Aharony
- School of Physics and Astronomy, Tel-Aviv University, Tel Aviv 6997801, Israel
| | - O Entin-Wohlman
- School of Physics and Astronomy, Tel-Aviv University, Tel Aviv 6997801, Israel
| | - M Goldstein
- School of Physics and Astronomy, Tel-Aviv University, Tel Aviv 6997801, Israel
| | - Y Dagan
- School of Physics and Astronomy, Tel-Aviv University, Tel Aviv 6997801, Israel
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4
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Kim D, Pandey J, Jeong J, Cho W, Lee S, Cho S, Yang H. Phase Engineering of 2D Materials. Chem Rev 2023; 123:11230-11268. [PMID: 37589590 DOI: 10.1021/acs.chemrev.3c00132] [Citation(s) in RCA: 3] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 08/18/2023]
Abstract
Polymorphic 2D materials allow structural and electronic phase engineering, which can be used to realize energy-efficient, cost-effective, and scalable device applications. The phase engineering covers not only conventional structural and metal-insulator transitions but also magnetic states, strongly correlated band structures, and topological phases in rich 2D materials. The methods used for the local phase engineering of 2D materials include various optical, geometrical, and chemical processes as well as traditional thermodynamic approaches. In this Review, we survey the precise manipulation of local phases and phase patterning of 2D materials, particularly with ideal and versatile phase interfaces for electronic and energy device applications. Polymorphic 2D materials and diverse quantum materials with their layered, vertical, and lateral geometries are discussed with an emphasis on the role and use of their phase interfaces. Various phase interfaces have demonstrated superior and unique performance in electronic and energy devices. The phase patterning leads to novel homo- and heterojunction structures of 2D materials with low-dimensional phase boundaries, which highlights their potential for technological breakthroughs in future electronic, quantum, and energy devices. Accordingly, we encourage researchers to investigate and exploit phase patterning in emerging 2D materials.
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Affiliation(s)
- Dohyun Kim
- Department of Physics, Korea Advanced Institute of Science and Technology (KAIST), Daejeon 34141, Korea
| | - Juhi Pandey
- Department of Physics, Korea Advanced Institute of Science and Technology (KAIST), Daejeon 34141, Korea
| | - Juyeong Jeong
- Department of Physics, Korea Advanced Institute of Science and Technology (KAIST), Daejeon 34141, Korea
| | - Woohyun Cho
- Department of Physics, Korea Advanced Institute of Science and Technology (KAIST), Daejeon 34141, Korea
| | - Seungyeon Lee
- Division of Chemical Engineering and Materials Science, Graduate Program in System Health Science and Engineering, Ewha Womans University, Seoul 03760, Korea
| | - Suyeon Cho
- Division of Chemical Engineering and Materials Science, Graduate Program in System Health Science and Engineering, Ewha Womans University, Seoul 03760, Korea
| | - Heejun Yang
- Department of Physics, Korea Advanced Institute of Science and Technology (KAIST), Daejeon 34141, Korea
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5
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Yokouchi T, Ikeda Y, Morimoto T, Shiomi Y. Giant Magnetochiral Anisotropy in Weyl Semimetal WTe_{2} Induced by Diverging Berry Curvature. PHYSICAL REVIEW LETTERS 2023; 130:136301. [PMID: 37067327 DOI: 10.1103/physrevlett.130.136301] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 11/18/2022] [Accepted: 03/08/2023] [Indexed: 06/19/2023]
Abstract
The concept of Berry curvature is essential for various transport phenomena. However, an effect of the Berry curvature on magnetochiral anisotropy, i.e., nonreciprocal magnetotransport, is still elusive. Here, we report that the Berry curvature induces the large magnetochiral anisotropy. In Weyl semimetal WTe_{2}, we observe the strong enhancement of the magnetochiral anisotropy when the Fermi level is located near the Weyl points. Notably, the maximal figure of merit γ[over ¯] reaches 1.2×10^{-6} m^{2} T^{-1} A^{-1}, which is the largest ever reported in bulk materials. Our semiclassical calculation shows that the diverging Berry curvature at the Weyl points strongly enhances the magnetochiral anisotropy.
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Affiliation(s)
- Tomoyuki Yokouchi
- Department of Basic Science, The University of Tokyo, Tokyo 152-8902, Japan
| | - Yuya Ikeda
- Department of Applied Physics, The University of Tokyo, Tokyo 113-8656, Japan
| | - Takahiro Morimoto
- Department of Applied Physics, The University of Tokyo, Tokyo 113-8656, Japan
| | - Yuki Shiomi
- Department of Basic Science, The University of Tokyo, Tokyo 152-8902, Japan
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6
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Li L, Wu Y, Liu X, Liu J, Ruan H, Zhi Z, Zhang Y, Huang P, Ji Y, Tang C, Yang Y, Che R, Kou X. Room-Temperature Gate-Tunable Nonreciprocal Charge Transport in Lattice-Matched InSb/CdTe Heterostructures. ADVANCED MATERIALS (DEERFIELD BEACH, FLA.) 2023; 35:e2207322. [PMID: 36526594 DOI: 10.1002/adma.202207322] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 08/11/2022] [Revised: 10/30/2022] [Indexed: 06/17/2023]
Abstract
Symmetry manipulation can be used to effectively tailor the physical order in solid-state systems. With the breaking of both the inversion and time-reversal symmetries, nonreciprocal magneto-transport may arise in nonmagnetic systems to enrich spin-orbit effects. Here, the observation of unidirectional magnetoresistance (UMR) in lattice-matched InSb/CdTe films is investigated up to room temperature. Benefiting from the strong built-in electric field of 0.13 V nm-1 in the heterojunction region, the resulting Rashba-type spin-orbit coupling and quantum confinement result in a distinct sinusoidal UMR signal with a nonreciprocal coefficient that is 1-2 orders of magnitude larger than most non-centrosymmetric materials at 298 K. Moreover, this heterostructure configuration enables highly efficient gate tuning of the rectification response, wherein the UMR amplitude is enhanced by 40%. The results of this study advocate the use of narrow-bandgap semiconductor-based hybrid systems with robust spin textures as suitable platforms for the pursuit of controllable chiral spin-orbit applications.
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Affiliation(s)
- Lun Li
- School of Information Science and Technology, ShanghaiTech University, Shanghai, 201210, China
| | - Yuyang Wu
- Laboratory of Advanced Materials, Shanghai Key Lab of Molecular Catalysis and Innovative Materials, Fudan University, Shanghai, 200438, China
- Department of Materials Science, Fudan University, Shanghai, 200438, China
| | - Xiaoyang Liu
- School of Information Science and Technology, ShanghaiTech University, Shanghai, 201210, China
- Shanghai Institute of Microsystem and Information Technology, Chinese Academy of Sciences, Shanghai, 200050, China
- University of Chinese Academy of Science, Beijing, 101408, China
| | - Jiuming Liu
- School of Information Science and Technology, ShanghaiTech University, Shanghai, 201210, China
| | - Hanzhi Ruan
- School of Information Science and Technology, ShanghaiTech University, Shanghai, 201210, China
| | - Zhenghang Zhi
- School of Information Science and Technology, ShanghaiTech University, Shanghai, 201210, China
- Shanghai Institute of Microsystem and Information Technology, Chinese Academy of Sciences, Shanghai, 200050, China
- University of Chinese Academy of Science, Beijing, 101408, China
| | - Yong Zhang
- School of Information Science and Technology, ShanghaiTech University, Shanghai, 201210, China
- Shanghai Institute of Microsystem and Information Technology, Chinese Academy of Sciences, Shanghai, 200050, China
- University of Chinese Academy of Science, Beijing, 101408, China
| | - Puyang Huang
- School of Information Science and Technology, ShanghaiTech University, Shanghai, 201210, China
| | - Yuchen Ji
- School of Physical Science and Technology, ShanghaiTech University, Shanghai, 201210, China
| | - Chenjia Tang
- School of Physical Science and Technology, ShanghaiTech University, Shanghai, 201210, China
- ShanghaiTech Laboratory for Topological Physics, ShanghaiTech University, Shanghai, 201210, China
| | - Yumeng Yang
- School of Information Science and Technology, ShanghaiTech University, Shanghai, 201210, China
| | - Renchao Che
- Laboratory of Advanced Materials, Shanghai Key Lab of Molecular Catalysis and Innovative Materials, Fudan University, Shanghai, 200438, China
- Department of Materials Science, Fudan University, Shanghai, 200438, China
| | - Xufeng Kou
- School of Information Science and Technology, ShanghaiTech University, Shanghai, 201210, China
- ShanghaiTech Laboratory for Topological Physics, ShanghaiTech University, Shanghai, 201210, China
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7
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Zhang Y, Kalappattil V, Liu C, Mehraeen M, Zhang SSL, Ding J, Erugu U, Chen Z, Tian J, Liu K, Tang J, Wu M. Large magnetoelectric resistance in the topological Dirac semimetal α-Sn. SCIENCE ADVANCES 2022; 8:eabo0052. [PMID: 35905193 PMCID: PMC9337753 DOI: 10.1126/sciadv.abo0052] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 01/06/2022] [Accepted: 06/14/2022] [Indexed: 06/15/2023]
Abstract
The spin-momentum locking of surface states in topological materials can produce a resistance that scales linearly with magnetic and electric fields. Such a bilinear magnetoelectric resistance (BMER) effect offers a new approach for information reading and field sensing applications, but the effects demonstrated so far are too weak or for low temperatures. This article reports the first observation of BMER effects in topological Dirac semimetals; the BMER responses were measured at room temperature and were substantially stronger than those reported previously. The experiments used topological Dirac semimetal α-Sn thin films grown on silicon substrates. The films showed BMER responses that are 106 times larger than previously measured at room temperature and are also larger than those previously obtained at low temperatures. These results represent a major advance toward realistic BMER applications. Significantly, the data also yield the first characterization of three-dimensional Fermi-level spin texture of topological surface states in α-Sn.
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Affiliation(s)
- Yuejie Zhang
- Department of Physics, Colorado State University, Fort Collins, CO 80523, USA
- School of Optical and Electronic Information, Huazhong University of Science and Technology, Wuhan, Hubei 430074, China
| | | | - Chuanpu Liu
- Department of Physics, Colorado State University, Fort Collins, CO 80523, USA
| | - M. Mehraeen
- Department of Physics, Case Western Reserve University, Cleveland, OH 44106, USA
| | - Steven S.-L. Zhang
- Department of Physics, Case Western Reserve University, Cleveland, OH 44106, USA
| | - Jinjun Ding
- Department of Physics, Colorado State University, Fort Collins, CO 80523, USA
| | - Uppalaiah Erugu
- Department of Physics and Astronomy, University of Wyoming, Laramie, WY 82071, USA
| | - Zhijie Chen
- Physics Department, Georgetown University, Washington, DC 20057, USA
| | - Jifa Tian
- Department of Physics and Astronomy, University of Wyoming, Laramie, WY 82071, USA
| | - Kai Liu
- Physics Department, Georgetown University, Washington, DC 20057, USA
| | - Jinke Tang
- Department of Physics and Astronomy, University of Wyoming, Laramie, WY 82071, USA
| | - Mingzhong Wu
- Department of Physics, Colorado State University, Fort Collins, CO 80523, USA
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8
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Koley A, Maiti SK, Pérez LM, Silva JHO, Laroze D. Possible Routes to Obtain Enhanced Magnetoresistance in a Driven Quantum Heterostructure with a Quasi-Periodic Spacer. MICROMACHINES 2021; 12:mi12091021. [PMID: 34577665 PMCID: PMC8466401 DOI: 10.3390/mi12091021] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 08/09/2021] [Revised: 08/23/2021] [Accepted: 08/24/2021] [Indexed: 11/16/2022]
Abstract
In this work, we perform a numerical study of magnetoresistance in a one-dimensional quantum heterostructure, where the change in electrical resistance is measured between parallel and antiparallel configurations of magnetic layers. This layered structure also incorporates a non-magnetic spacer, subjected to quasi-periodic potentials, which is centrally clamped between two ferromagnetic layers. The efficiency of the magnetoresistance is further tuned by injecting unpolarized light on top of the two sided magnetic layers. Modulating the characteristic properties of different layers, the value of magnetoresistance can be enhanced significantly. The site energies of the spacer is modified through the well-known Aubry-André and Harper (AAH) potential, and the hopping parameter of magnetic layers is renormalized due to light irradiation. We describe the Hamiltonian of the layered structure within a tight-binding (TB) framework and investigate the transport properties through this nanojunction following Green's function formalism. The Floquet-Bloch (FB) anstaz within the minimal coupling scheme is introduced to incorporate the effect of light irradiation in TB Hamiltonian. Several interesting features of magnetotransport properties are represented considering the interplay between cosine modulated site energies of the central region and the hopping integral of the magnetic regions that are subjected to light irradiation. Finally, the effect of temperature on magnetoresistance is also investigated to make the model more realistic and suitable for device designing. Our analysis is purely a numerical one, and it leads to some fundamental prescriptions of obtaining enhanced magnetoresistance in multilayered systems.
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Affiliation(s)
- Arpita Koley
- Physics and Applied Mathematics Unit, Indian Statistical Institute, 203 Barrackpore Trunk Road, Kolkata 700 108, India;
| | - Santanu K. Maiti
- Physics and Applied Mathematics Unit, Indian Statistical Institute, 203 Barrackpore Trunk Road, Kolkata 700 108, India;
- Correspondence:
| | - Laura M. Pérez
- Instituto de Alta Investigación, Universidad de Tarapacá, Casilla 7D, Arica 1000000, Chile; (L.M.P.); (D.L.)
| | - Judith Helena Ojeda Silva
- Grupo de Física de Materiales, Universidad Pedagógica y Tecnológica de Colombia, Tunja 150003, Colombia;
- Laboratorio de Química Teórica y Computacional, Grupo de Investigación Química-Física Molecular y Modelamiento Computacional (QUIMOL), Facultad de Ciencias, Universidad Pedagógica y Tecnológica de Colombia, Tunja 150003, Colombia
| | - David Laroze
- Instituto de Alta Investigación, Universidad de Tarapacá, Casilla 7D, Arica 1000000, Chile; (L.M.P.); (D.L.)
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9
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Kumar D, Hsu CH, Sharma R, Chang TR, Yu P, Wang J, Eda G, Liang G, Yang H. Room-temperature nonlinear Hall effect and wireless radiofrequency rectification in Weyl semimetal TaIrTe 4. NATURE NANOTECHNOLOGY 2021; 16:421-425. [PMID: 33495620 DOI: 10.1038/s41565-020-00839-3] [Citation(s) in RCA: 44] [Impact Index Per Article: 14.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 06/17/2020] [Accepted: 12/11/2020] [Indexed: 06/12/2023]
Abstract
The nonlinear Hall effect (NLHE), the phenomenon in which a transverse voltage can be produced without a magnetic field, provides a potential alternative for rectification or frequency doubling1,2. However, the low-temperature detection of the NLHE limits its applications3,4. Here, we report the room-temperature NLHE in a type-II Weyl semimetal TaIrTe4, which hosts a robust NLHE due to broken inversion symmetry and large band overlapping at the Fermi level. We also observe a temperature-induced sign inversion of the NLHE in TaIrTe4. Our theoretical calculations suggest that the observed sign inversion is a result of a temperature-induced shift in the chemical potential, indicating a direct correlation of the NLHE with the electronic structure at the Fermi surface. Finally, on the basis of the observed room-temperature NLHE in TaIrTe4 we demonstrate the wireless radiofrequency (RF) rectification with zero external bias and magnetic field. This work opens a door to realizing room-temperature applications based on the NLHE in Weyl semimetals.
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Affiliation(s)
- Dushyant Kumar
- Department of Electrical and Computer Engineering, National University of Singapore, Singapore, Singapore
| | - Chuang-Han Hsu
- Department of Electrical and Computer Engineering, National University of Singapore, Singapore, Singapore
| | - Raghav Sharma
- Department of Electrical and Computer Engineering, National University of Singapore, Singapore, Singapore
| | - Tay-Rong Chang
- Department of Physics, National Cheng Kung University, Tainan, Taiwan
- Center for Quantum Frontiers of Research & Technology (QFort), National Cheng Kung University, Tainan, Taiwan
| | - Peng Yu
- State Key Laboratory of Optoelectronic Materials and Technologies, School of Materials Science and Engineering, Sun Yat-sen University, Guangzhou, People's Republic of China
| | - Junyong Wang
- Centre for Advanced 2D Materials, National University of Singapore, Singapore, Singapore
- Department of Physics, National University of Singapore, Singapore, Singapore
| | - Goki Eda
- Centre for Advanced 2D Materials, National University of Singapore, Singapore, Singapore
- Department of Physics, National University of Singapore, Singapore, Singapore
- Department of Chemistry, National University of Singapore, Singapore, Singapore
| | - Gengchiau Liang
- Department of Electrical and Computer Engineering, National University of Singapore, Singapore, Singapore
| | - Hyunsoo Yang
- Department of Electrical and Computer Engineering, National University of Singapore, Singapore, Singapore.
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10
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Nonreciprocal charge transport up to room temperature in bulk Rashba semiconductor α-GeTe. Nat Commun 2021; 12:540. [PMID: 33483483 PMCID: PMC7822853 DOI: 10.1038/s41467-020-20840-7] [Citation(s) in RCA: 15] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/25/2020] [Accepted: 12/22/2020] [Indexed: 11/08/2022] Open
Abstract
Nonmagnetic Rashba systems with broken inversion symmetry are expected to exhibit nonreciprocal charge transport, a new paradigm of unidirectional magnetoresistance in the absence of ferromagnetic layer. So far, most work on nonreciprocal transport has been solely limited to cryogenic temperatures, which is a major obstacle for exploiting the room-temperature two-terminal devices based on such a nonreciprocal response. Here, we report a nonreciprocal charge transport behavior up to room temperature in semiconductor α-GeTe with coexisting the surface and bulk Rashba states. The combination of the band structure measurements and theoretical calculations strongly suggest that the nonreciprocal response is ascribed to the giant bulk Rashba spin splitting rather than the surface Rashba states. Remarkably, we find that the magnitude of the nonreciprocal response shows an unexpected non-monotonical dependence on temperature. The extended theoretical model based on the second-order spin-orbit coupled magnetotransport enables us to establish the correlation between the nonlinear magnetoresistance and the spin textures in the Rashba system. Our findings offer significant fundamental insight into the physics underlying the nonreciprocity and may pave a route for future rectification devices.
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11
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Yasuda K, Morimoto T, Yoshimi R, Mogi M, Tsukazaki A, Kawamura M, Takahashi KS, Kawasaki M, Nagaosa N, Tokura Y. Large non-reciprocal charge transport mediated by quantum anomalous Hall edge states. NATURE NANOTECHNOLOGY 2020; 15:831-835. [PMID: 32661369 DOI: 10.1038/s41565-020-0733-2] [Citation(s) in RCA: 12] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 11/17/2019] [Accepted: 06/08/2020] [Indexed: 06/11/2023]
Abstract
The topological nature of the quantum anomalous Hall effect (QAHE) causes a dissipationless chiral edge current at the sample boundary1,2. Of fundamental interest is whether the chirality of the band structure manifests itself in charge transport properties. Here we report the observation of large non-reciprocal charge transport3 in a magnetic topological insulator, Cr-doped (Bi,Sb)2Te3. When the surface massive Dirac band is slightly carrier doped by a gate voltage, the edge state starts to dissipate and exhibits a current-direction-dependent resistance with a directional difference as large as 26%. The polarity of this diode effect depends on the magnetization direction as well as on the carrier type, electrons or holes. The correlation between the non-reciprocal resistance and the Hall resistance indicates that the non-reciprocity originates from the interplay between the chiral edge state and the Dirac surface state.
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Affiliation(s)
- Kenji Yasuda
- Department of Applied Physics and Quantum-Phase Electronics Center (QPEC), University of Tokyo, Tokyo, Japan.
- Department of Physics, Massachusetts Institute of Technology, Cambridge, MA, USA.
| | - Takahiro Morimoto
- Department of Applied Physics and Quantum-Phase Electronics Center (QPEC), University of Tokyo, Tokyo, Japan
- PRESTO, Japan Science and Technology Agency, Chiyoda-ku, Japan
| | - Ryutaro Yoshimi
- RIKEN Center for Emergent Matter Science (CEMS), Wako, Japan
| | - Masataka Mogi
- Department of Applied Physics and Quantum-Phase Electronics Center (QPEC), University of Tokyo, Tokyo, Japan
| | | | - Minoru Kawamura
- RIKEN Center for Emergent Matter Science (CEMS), Wako, Japan
| | - Kei S Takahashi
- PRESTO, Japan Science and Technology Agency, Chiyoda-ku, Japan
- RIKEN Center for Emergent Matter Science (CEMS), Wako, Japan
| | - Masashi Kawasaki
- Department of Applied Physics and Quantum-Phase Electronics Center (QPEC), University of Tokyo, Tokyo, Japan
- RIKEN Center for Emergent Matter Science (CEMS), Wako, Japan
| | - Naoto Nagaosa
- Department of Applied Physics and Quantum-Phase Electronics Center (QPEC), University of Tokyo, Tokyo, Japan
- RIKEN Center for Emergent Matter Science (CEMS), Wako, Japan
| | - Yoshinori Tokura
- Department of Applied Physics and Quantum-Phase Electronics Center (QPEC), University of Tokyo, Tokyo, Japan.
- RIKEN Center for Emergent Matter Science (CEMS), Wako, Japan.
- Tokyo College, University of Tokyo, Tokyo, Japan.
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Chen M, Lee K, Li J, Cheng L, Wang Q, Cai K, Chia EEM, Chang H, Yang H. Anisotropic Picosecond Spin-Photocurrent from Weyl Semimetal WTe 2. ACS NANO 2020; 14:3539-3545. [PMID: 32160456 DOI: 10.1021/acsnano.9b09828] [Citation(s) in RCA: 15] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/10/2023]
Abstract
The generation and detection of ultrafast spin current, preferably reaching a frequency up to terahertz, is the core of spintronics. Studies have shown that the Weyl semimetal WTe2 is of great potential in generating spin currents. However, the prior studies have been limited to the static measurements with the in-plane spin orientation. In this work, we demonstrate a picosecond spin-photocurrent in a Td-WTe2 thin film via a terahertz time domain spectroscopy with a circularly polarized laser excitation. The anisotropic dependence of the circular photogalvanic effect (CPGE) in the terahertz emission reveals that the picosecond spin-photocurrent is generated along the rotational asymmetry a-axis. Notably, the generated spins are aligned along the out-of-plane direction under the light normally incident to the film surface, which provides an efficient means to manipulate magnetic devices with perpendicular magnetic anisotropy. A spin-splitting band induced by intrinsic inversion symmetry breaking enables the manipulation of a spin current by modulating the helicity of the laser excitation. Moreover, CPGE nearly vanishes at a transition temperature of ∼175 K due to the carrier compensation. Our work provides an insight into the dynamic behavior of the anisotropic spin-photocurrent of Td-WTe2 in terahertz frequencies and shows a great potential for the future development of terahertz-spintronic devices with Weyl semimetals.
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Affiliation(s)
- Mengji Chen
- Department of Electrical and Computer Engineering and NUSNNI, National University of Singapore, 117576, Singapore
| | - Kyusup Lee
- Department of Electrical and Computer Engineering and NUSNNI, National University of Singapore, 117576, Singapore
| | - Jie Li
- Center for Joining and Electronic Packaging, State Key Laboratory of Material Processing and Die & Mould Technology, School of Materials Science and Engineering, Huazhong University of Science and Technology, Wuhan 430074, China
| | - Liang Cheng
- Division of Physics and Applied Physics, School of Physical and Mathematical Sciences, Nanyang Technological University, 637371, Singapore
| | - Qisheng Wang
- Department of Electrical and Computer Engineering and NUSNNI, National University of Singapore, 117576, Singapore
| | - Kaiming Cai
- Department of Electrical and Computer Engineering and NUSNNI, National University of Singapore, 117576, Singapore
| | - Elbert E M Chia
- Division of Physics and Applied Physics, School of Physical and Mathematical Sciences, Nanyang Technological University, 637371, Singapore
| | - Haixin Chang
- Center for Joining and Electronic Packaging, State Key Laboratory of Material Processing and Die & Mould Technology, School of Materials Science and Engineering, Huazhong University of Science and Technology, Wuhan 430074, China
| | - Hyunsoo Yang
- Department of Electrical and Computer Engineering and NUSNNI, National University of Singapore, 117576, Singapore
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