1
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Cui Y, Li Z, Chen H, Wu Y, Chen Y, Pei K, Wu T, Xie N, Che R, Qiu X, Liu Y, Yuan Z, Wu Y. Antisymmetric planar Hall effect in rutile oxide films induced by the Lorentz force. Sci Bull (Beijing) 2024; 69:2362-2369. [PMID: 38944633 DOI: 10.1016/j.scib.2024.06.009] [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: 03/02/2024] [Revised: 05/06/2024] [Accepted: 06/03/2024] [Indexed: 07/01/2024]
Abstract
The conventional Hall effect is linearly proportional to the field component or magnetization component perpendicular to a film. Despite the increasing theoretical proposals on the Hall effect to the in-plane field or magnetization in various special systems induced by the Berry curvature, such an unconventional Hall effect has only been experimentally reported in Weyl semimetals and in a heterodimensional superlattice. Here, we report an unambiguous experimental observation of the antisymmetric planar Hall effect (APHE) with respect to the in-plane magnetic field in centrosymmetric rutile RuO2 and IrO2 single-crystal films. The measured Hall resistivity is found to be linearly proportional to the component of the applied in-plane magnetic field along a particular crystal axis and to be independent of the current direction or temperature. Both the experimental observations and theoretical calculations confirm that the APHE in rutile oxide films is induced by the Lorentz force. Our findings can be generalized to ferromagnetic materials for the discovery of anomalous Hall effects and quantum anomalous Hall effects induced by in-plane magnetization. In addition to significantly expanding knowledge of the Hall effect, this work opens the door to explore new members in the Hall effect family.
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Affiliation(s)
- Yongwei Cui
- Department of Physics, State Key Laboratory of Surface Physics, Fudan University, Shanghai 200433, China
| | - Zhaoqing Li
- Institute for Nanoelectronic Devices and Quantum Computing, Fudan University, Shanghai 200433, China; Interdisciplinary Center for Theoretical Physics and Information Sciences, Fudan University, Shanghai 200433, China
| | - Haoran Chen
- Department of Physics, State Key Laboratory of Surface Physics, Fudan University, Shanghai 200433, China
| | - Yunzhuo Wu
- Department of Physics, State Key Laboratory of Surface Physics, Fudan University, Shanghai 200433, China
| | - Yue Chen
- Institute for Nanoelectronic Devices and Quantum Computing, Fudan University, Shanghai 200433, China; Interdisciplinary Center for Theoretical Physics and Information Sciences, Fudan University, Shanghai 200433, China; Center for Advanced Quantum Studies and Department of Physics, Beijing Normal University, Beijing 100875, China
| | - Ke Pei
- Laboratory of Advanced Materials, Shanghai Key Lab of Molecular Catalysis and Innovative Materials, Academy for Engineering & Technology, Fudan University, Shanghai 200438, China
| | - Tong Wu
- Department of Physics, State Key Laboratory of Surface Physics, Fudan University, Shanghai 200433, China
| | - Nian Xie
- Shanghai Key Laboratory of Special Artificial Microstructure Materials and Technology, School of Physics Science and Engineering, Tongji University, Shanghai 200092, China
| | - Renchao Che
- Laboratory of Advanced Materials, Shanghai Key Lab of Molecular Catalysis and Innovative Materials, Academy for Engineering & Technology, Fudan University, Shanghai 200438, China; Zhejiang Laboratory, Hangzhou 311100, China
| | - Xuepeng Qiu
- Shanghai Key Laboratory of Special Artificial Microstructure Materials and Technology, School of Physics Science and Engineering, Tongji University, Shanghai 200092, China
| | - Yi Liu
- Center for Advanced Quantum Studies and Department of Physics, Beijing Normal University, Beijing 100875, China
| | - Zhe Yuan
- Institute for Nanoelectronic Devices and Quantum Computing, Fudan University, Shanghai 200433, China; Interdisciplinary Center for Theoretical Physics and Information Sciences, Fudan University, Shanghai 200433, China.
| | - Yizheng Wu
- Department of Physics, State Key Laboratory of Surface Physics, Fudan University, Shanghai 200433, China; Shanghai Research Center for Quantum Sciences, Shanghai 201315, China; Shanghai Key Laboratory of Metasurfaces for Light Manipulation, Fudan University, Shanghai 200433, China.
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2
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Wang H, Huang YX, Liu H, Feng X, Zhu J, Wu W, Xiao C, Yang SA. Orbital Origin of the Intrinsic Planar Hall Effect. PHYSICAL REVIEW LETTERS 2024; 132:056301. [PMID: 38364160 DOI: 10.1103/physrevlett.132.056301] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 11/10/2022] [Revised: 10/12/2023] [Accepted: 12/20/2023] [Indexed: 02/18/2024]
Abstract
Recent experiments reported an antisymmetric planar Hall effect, where the Hall current is odd in the in plane magnetic field and scales linearly with both electric and magnetic fields applied. Existing theories rely exclusively on a spin origin, which requires spin-orbit coupling to take effect. Here, we develop a general theory for the intrinsic planar Hall effect (IPHE), highlighting a previously unknown orbital mechanism and connecting it to a band geometric quantity-the anomalous orbital polarizability (AOP). Importantly, the orbital mechanism does not request spin-orbit coupling, so sizable IPHE can occur and is dominated by an orbital contribution in systems with weak spin-orbit coupling. Combined with first-principles calculations, we demonstrate our theory with quantitative evaluation for bulk materials TaSb_{2}, NbAs_{2}, and SrAs_{3}. We further show that AOP and its associated orbital IPHE can be greatly enhanced at topological band crossings, offering a new way to probe topological materials.
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Affiliation(s)
- Hui Wang
- Research Laboratory for Quantum Materials, Singapore University of Technology and Design, Singapore 487372, Singapore
- Division of Physics and Applied Physics, School of Physical and Mathematical Sciences, Nanyang Technological University, Singapore 637371, Singapore
| | - Yue-Xin Huang
- Research Laboratory for Quantum Materials, Singapore University of Technology and Design, Singapore 487372, Singapore
- School of Sciences, Great Bay University, Dongguan 523000, China
- Great Bay Institute for Advanced Study, Dongguan 523000, China
| | - Huiying Liu
- Research Laboratory for Quantum Materials, Singapore University of Technology and Design, Singapore 487372, Singapore
- School of Physics, Beihang University, Beijing 100191, China
| | - Xiaolong Feng
- Research Laboratory for Quantum Materials, Singapore University of Technology and Design, Singapore 487372, Singapore
- Max Planck Institute for Chemical Physics of Solids, Nöthnitzer Strasse 40, D-01187 Dresden, Germany
| | - Jiaojiao Zhu
- Research Laboratory for Quantum Materials, Singapore University of Technology and Design, Singapore 487372, Singapore
| | - Weikang Wu
- Research Laboratory for Quantum Materials, Singapore University of Technology and Design, Singapore 487372, Singapore
- Key Laboratory for Liquid-Solid Structural Evolution and Processing of Materials, Ministry of Education, Shandong University, Jinan 250061, China
| | - Cong Xiao
- Institute of Applied Physics and Materials Engineering, University of Macau, Macau, China
- Department of Physics, The University of Hong Kong, Hong Kong, China
- HKU-UCAS Joint Institute of Theoretical and Computational Physics at Hong Kong, Hong Kong, China
| | - Shengyuan A Yang
- Institute of Applied Physics and Materials Engineering, University of Macau, Macau, China
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3
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Huang YX, Feng X, Wang H, Xiao C, Yang SA. Intrinsic Nonlinear Planar Hall Effect. PHYSICAL REVIEW LETTERS 2023; 130:126303. [PMID: 37027844 DOI: 10.1103/physrevlett.130.126303] [Citation(s) in RCA: 3] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 08/07/2022] [Accepted: 02/23/2023] [Indexed: 06/19/2023]
Abstract
We propose an intrinsic nonlinear planar Hall effect, which is of band geometric origin, independent of scattering, and scales with the second order of electric field and first order of magnetic field. We show that this effect is less symmetry constrained compared with other nonlinear transport effects and is supported in a large class of nonmagnetic polar and chiral crystals. Its characteristic angular dependence provides an effective way to control the nonlinear output. Combined with first-principles calculations, we evaluate this effect in the Janus monolayer MoSSe and report experimentally measurable results. Our work reveals an intrinsic transport effect, which offers a new tool for material characterization and a new mechanism for nonlinear device application.
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Affiliation(s)
- Yue-Xin Huang
- Research Laboratory for Quantum Materials, Singapore University of Technology and Design, Singapore 487372, Singapore
| | - Xiaolong Feng
- Research Laboratory for Quantum Materials, Singapore University of Technology and Design, Singapore 487372, Singapore
| | - Hui Wang
- Research Laboratory for Quantum Materials, Singapore University of Technology and Design, Singapore 487372, Singapore
| | - Cong Xiao
- Department of Physics, The University of Hong Kong, Hong Kong, China
- HKU-UCAS Joint Institute of Theoretical and Computational Physics at Hong Kong, Hong Kong, China
| | - Shengyuan A Yang
- Research Laboratory for Quantum Materials, Singapore University of Technology and Design, Singapore 487372, Singapore
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4
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Seifert TS, Martens U, Radu F, Ribow M, Berritta M, Nádvorník L, Starke R, Jungwirth T, Wolf M, Radu I, Münzenberg M, Oppeneer PM, Woltersdorf G, Kampfrath T. Frequency-Independent Terahertz Anomalous Hall Effect in DyCo 5 , Co 32 Fe 68 , and Gd 27 Fe 73 Thin Films from DC to 40 THz. ADVANCED MATERIALS (DEERFIELD BEACH, FLA.) 2021; 33:e2007398. [PMID: 33656190 DOI: 10.1002/adma.202007398] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 10/29/2020] [Revised: 12/21/2020] [Indexed: 06/12/2023]
Abstract
The anomalous Hall effect (AHE) is a fundamental spintronic charge-to-charge-current conversion phenomenon and closely related to spin-to-charge-current conversion by the spin Hall effect. Future high-speed spintronic devices will crucially rely on such conversion phenomena at terahertz (THz) frequencies. Here, it is revealed that the AHE remains operative from DC up to 40 THz with a flat frequency response in thin films of three technologically relevant magnetic materials: DyCo5 , Co32 Fe68 , and Gd27 Fe73 . The frequency-dependent conductivity-tensor elements σxx and σyx are measured, and good agreement with DC measurements is found. The experimental findings are fully consistent with ab initio calculations of σyx for CoFe and highlight the role of the large Drude scattering rate (≈100 THz) of metal thin films, which smears out any sharp spectral features of the THz AHE. Finally, it is found that the intrinsic contribution to the THz AHE dominates over the extrinsic mechanisms for the Co32 Fe68 sample. The results imply that the AHE and related effects such as the spin Hall effect are highly promising ingredients of future THz spintronic devices reliably operating from DC to 40 THz and beyond.
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Affiliation(s)
- Tom S Seifert
- Department of Physics, Freie Universität Berlin, Berlin, 14195, Germany
- Department of Physical Chemistry, Fritz-Haber-Institute of the Max-Planck-Society, Berlin, 14195, Germany
| | - Ulrike Martens
- Institute of Physics, University of Greifswald, Greifswald, 17489, Germany
| | - Florin Radu
- Helmholtz-Zentrum Berlin für Materialien und Energie, Albert-Einstein-Str. 15, Berlin, 12489, Germany
| | - Mirkow Ribow
- Institute of Physics, Martin-Luther Universität Halle-Wittenberg, Halle (Saale), 06120, Germany
| | - Marco Berritta
- Department of Physics and Astronomy, Uppsala University, P.O. Box 516, Uppsala, SE-75120, Sweden
| | - Lukáš Nádvorník
- Faculty of Mathematics and Physics, Charles University, Ke Kalovu 2027/3, Prague, 12116, Czech Republic
| | | | - Tomas Jungwirth
- Institute of Physics, Czech Academy of Sciences, Cukrovarnicka 10, Praha, 6, 162 00, Czech Republic
- School of Physics and Astronomy, University of Nottingham, Nottingham, NG7 2RD, UK
| | - Martin Wolf
- Department of Physical Chemistry, Fritz-Haber-Institute of the Max-Planck-Society, Berlin, 14195, Germany
| | - Ilie Radu
- Department of Physics, Freie Universität Berlin, Berlin, 14195, Germany
- Max-Born Institute for Nonlinear Optics and Short Pulse Spectroscopy, Max-Born-Str. 2A, Berlin, 12489, Germany
| | - Markus Münzenberg
- Institute of Physics, University of Greifswald, Greifswald, 17489, Germany
| | - Peter M Oppeneer
- Institute of Physics, Martin-Luther Universität Halle-Wittenberg, Halle (Saale), 06120, Germany
| | - Georg Woltersdorf
- Institute of Physics, Martin-Luther Universität Halle-Wittenberg, Halle (Saale), 06120, Germany
| | - Tobias Kampfrath
- Department of Physics, Freie Universität Berlin, Berlin, 14195, Germany
- Department of Physical Chemistry, Fritz-Haber-Institute of the Max-Planck-Society, Berlin, 14195, Germany
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5
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Yang SY, Noky J, Gayles J, Dejene FK, Sun Y, Dörr M, Skourski Y, Felser C, Ali MN, Liu E, Parkin SSP. Field-Modulated Anomalous Hall Conductivity and Planar Hall Effect in Co 3Sn 2S 2 Nanoflakes. NANO LETTERS 2020; 20:7860-7867. [PMID: 32986438 PMCID: PMC7662920 DOI: 10.1021/acs.nanolett.0c02219] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 05/26/2020] [Revised: 09/27/2020] [Indexed: 06/11/2023]
Abstract
Time-reversal-symmetry-breaking Weyl semimetals (WSMs) have attracted great attention recently because of the interplay between intrinsic magnetism and topologically nontrivial electrons. Here, we present anomalous Hall and planar Hall effect studies on Co3Sn2S2 nanoflakes, a magnetic WSM hosting stacked Kagome lattice. The reduced thickness modifies the magnetic properties of the nanoflake, resulting in a 15-time larger coercive field compared with the bulk, and correspondingly modifies the transport properties. A 22% enhancement of the intrinsic anomalous Hall conductivity (AHC), as compared to bulk material, was observed. A magnetic field-modulated AHC, which may be related to the changing Weyl point separation with magnetic field, was also found. Furthermore, we showed that the PHE in a hard magnetic WSM is a complex interplay between ferromagnetism, orbital magnetoresistance, and chiral anomaly. Our findings pave the way for a further understanding of exotic transport features in the burgeoning field of magnetic topological phases.
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Affiliation(s)
- Shuo-Ying Yang
- Max-Planck
Institute of Microstructure Physics, 06120 Halle (Saale), Germany
| | - Jonathan Noky
- Max
Planck Institute for Chemical Physics of Solids, 00187 Dresden, Germany
| | - Jacob Gayles
- Max
Planck Institute for Chemical Physics of Solids, 00187 Dresden, Germany
- Department
of Physics, University of South Florida, Tampa, Florida 33620, United States
| | - Fasil Kidane Dejene
- Max-Planck
Institute of Microstructure Physics, 06120 Halle (Saale), Germany
- Department
of Physics, Loughborough University, Leicestershire LE11 3TU, United Kingdom
| | - Yan Sun
- Max
Planck Institute for Chemical Physics of Solids, 00187 Dresden, Germany
| | - Mathias Dörr
- Dresden
University of Technology, 01602 Dresden, Germany
| | - Yurii Skourski
- Dresden
High Magnetic Field Laboratory (HLD-EMFL), Helmholtz-Zentrum Dresden-Rossendorf, 01328 Dresden, Germany
| | - Claudia Felser
- Max
Planck Institute for Chemical Physics of Solids, 00187 Dresden, Germany
| | - Mazhar Nawaz Ali
- Max-Planck
Institute of Microstructure Physics, 06120 Halle (Saale), Germany
| | - Enke Liu
- Max
Planck Institute for Chemical Physics of Solids, 00187 Dresden, Germany
- Institute
of Physics, Chinese Academy of Science, Beijing 100190, China
| | - Stuart S. P. Parkin
- Max-Planck
Institute of Microstructure Physics, 06120 Halle (Saale), Germany
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6
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Safranski C, Sun JZ, Xu JW, Kent AD. Planar Hall Driven Torque in a Ferromagnet/Nonmagnet/Ferromagnet System. PHYSICAL REVIEW LETTERS 2020; 124:197204. [PMID: 32469573 DOI: 10.1103/physrevlett.124.197204] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 10/18/2019] [Accepted: 04/22/2020] [Indexed: 06/11/2023]
Abstract
An important goal of spintronics is to covert a charge current into a spin current with a controlled spin polarization that can exert torques on an adjacent magnetic layer. Here we demonstrate such torques in a two ferromagnet system. A CoNi multilayer is used as a spin current source in a sample with structure CoNi/Au/CoFeB. Spin torque ferromagnetic resonance is used to measure the torque on the CoFeB layer. The response as a function of the applied field angle and current is consistent with the symmetry expected for a torque produced by the planar Hall effect originating in CoNi. We find the strength of this effect to be comparable to that of the spin Hall effect in platinum, indicating that the planar Hall effect holds potential as a spin current source with a controllable polarization direction.
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Affiliation(s)
| | - Jonathan Z Sun
- IBM T. J. Watson Research Center, Yorktown Heights, New York 10598, USA
| | - Jun-Wen Xu
- Center for Quantum Phenomena, Department of Physics, New York University, New York, New York 10003, USA
| | - Andrew D Kent
- Center for Quantum Phenomena, Department of Physics, New York University, New York, New York 10003, USA
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7
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Jin L, Jia K, Zhang D, Liu B, Meng H, Tang X, Zhong Z, Zhang H. Effect of Interfacial Roughness Spin Scattering on the Spin Current Transport in YIG/NiO/Pt Heterostructures. ACS APPLIED MATERIALS & INTERFACES 2019; 11:35458-35467. [PMID: 31483597 DOI: 10.1021/acsami.9b12125] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/10/2023]
Abstract
Interfacial properties play a vital role in spin current injection from the ferromagnetic (FM) layer into the nonmagnetic (NM) layer. So far, impedance matching and spin-orbit coupling are two important, well-known factors in spin current transport in FM/NM heterostructures. In this work, the spin current transport in Y3Fe5O12 (YIG)/NiO/Pt heterostructures was investigated by spin Hall magnetoresistance and inverse spin Hall effect measurements. By inserting a layer of antiferromagnetic insulator NiO, the magnetic proximity effect affecting the Pt atoms owing to YIG and the anomalous spin Hall voltage can be efficiently blocked. Ferromagnetic resonance and spin pumping measurements verified that the ferromagnetic/antiferromagnetic exchange coupling inhibits transmission of the spin current at the YIG/NiO interface when the NiO layer is thick. Atomic force microscopy and spherical aberration-corrected transmission electron microscopy proved that the strong interfacial roughness-enhanced spin scattering between NiO and Pt can greatly increase both the inverse spin Hall voltage and the spin Hall magnetoresistance when the NiO layer is thin or even discontinuous. This interface roughness-dominated spin scattering mechanism based on the YIG/NiO/Pt heterostructure is a new discovery, and there is significant potential for exploiting this mechanism in the construction of low-dissipation spintronic devices with an efficient spin current injection.
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Affiliation(s)
- Lichuan Jin
- State Key Laboratory of Electronic Thin Films and Integrated Devices , University of Electronic Science and Technology of China , Chengdu , 610054 , China
| | - Kancheng Jia
- State Key Laboratory of Electronic Thin Films and Integrated Devices , University of Electronic Science and Technology of China , Chengdu , 610054 , China
| | - Dainan Zhang
- State Key Laboratory of Electronic Thin Films and Integrated Devices , University of Electronic Science and Technology of China , Chengdu , 610054 , China
| | - Bo Liu
- Zhejiang Hikstor Technology Co., Ltd. , Hangzhou , 310000 , China
| | - Hao Meng
- Zhejiang Hikstor Technology Co., Ltd. , Hangzhou , 310000 , China
| | - Xiaoli Tang
- State Key Laboratory of Electronic Thin Films and Integrated Devices , University of Electronic Science and Technology of China , Chengdu , 610054 , China
| | - Zhiyong Zhong
- State Key Laboratory of Electronic Thin Films and Integrated Devices , University of Electronic Science and Technology of China , Chengdu , 610054 , China
| | - Huaiwu Zhang
- State Key Laboratory of Electronic Thin Films and Integrated Devices , University of Electronic Science and Technology of China , Chengdu , 610054 , China
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8
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He P, Zhang SSL, Zhu D, Shi S, Heinonen OG, Vignale G, Yang H. Nonlinear Planar Hall Effect. PHYSICAL REVIEW LETTERS 2019; 123:016801. [PMID: 31386424 DOI: 10.1103/physrevlett.123.016801] [Citation(s) in RCA: 16] [Impact Index Per Article: 3.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 12/12/2018] [Revised: 05/07/2019] [Indexed: 06/10/2023]
Abstract
An intriguing property of a three-dimensional (3D) topological insulator (TI) is the existence of surface states with spin-momentum locking, which offers a new frontier of exploration in spintronics. Here, we report the observation of a new type of Hall effect in a 3D TI Bi_{2}Se_{3} film. The Hall resistance scales linearly with both the applied electric and magnetic fields and exhibits a π/2 angle offset with respect to its longitudinal counterpart, in contrast to the usual angle offset of π/4 between the linear planar Hall effect and the anisotropic magnetoresistance. This novel nonlinear planar Hall effect originates from the conversion of a nonlinear transverse spin current to a charge current due to the concerted actions of spin-momentum locking and time-reversal symmetry breaking, which also exists in a wide class of noncentrosymmetric materials with a large span of magnitude. It provides a new way to characterize and utilize the nonlinear spin-to-charge conversion in a variety of topological quantum materials.
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Affiliation(s)
- Pan He
- Department of Electrical and Computer Engineering, and NUSNNI, National University of Singapore, 117576 Singapore
| | - Steven S-L Zhang
- Materials Science Division, Argonne National Laboratory, Lemont, Illinois 60439, USA
- Department of Physics and Astronomy, University of Missouri, Columbia, Missouri 65211, USA
| | - Dapeng Zhu
- Department of Electrical and Computer Engineering, and NUSNNI, National University of Singapore, 117576 Singapore
| | - Shuyuan Shi
- Department of Electrical and Computer Engineering, and NUSNNI, National University of Singapore, 117576 Singapore
| | - Olle G Heinonen
- Materials Science Division, Argonne National Laboratory, Lemont, Illinois 60439, USA
| | - Giovanni Vignale
- Department of Physics and Astronomy, University of Missouri, Columbia, Missouri 65211, USA
| | - Hyunsoo Yang
- Department of Electrical and Computer Engineering, and NUSNNI, National University of Singapore, 117576 Singapore
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9
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Bodnar SY, Šmejkal L, Turek I, Jungwirth T, Gomonay O, Sinova J, Sapozhnik AA, Elmers HJ, Kläui M, Jourdan M. Writing and reading antiferromagnetic Mn 2Au by Néel spin-orbit torques and large anisotropic magnetoresistance. Nat Commun 2018; 9:348. [PMID: 29367633 PMCID: PMC5783935 DOI: 10.1038/s41467-017-02780-x] [Citation(s) in RCA: 98] [Impact Index Per Article: 16.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/20/2017] [Accepted: 12/26/2017] [Indexed: 11/17/2022] Open
Abstract
Using antiferromagnets as active elements in spintronics requires the ability to manipulate and read-out the Néel vector orientation. Here we demonstrate for Mn2Au, a good conductor with a high ordering temperature suitable for applications, reproducible switching using current pulse generated bulk spin-orbit torques and read-out by magnetoresistance measurements. Reversible and consistent changes of the longitudinal resistance and planar Hall voltage of star-patterned epitaxial Mn2Au(001) thin films were generated by pulse current densities of ≃107 A/cm2. The symmetry of the torques agrees with theoretical predictions and a large read-out magnetoresistance effect of more than ≃6% is reproduced by ab initio transport calculations. The zero net moment of antiferromagnets makes them insensitive to magnetic fields and enables ultrafast dynamics promising for novel spintronics. Here the authors achieved pulse current induced Néel vector switching in Mn2Au(001) epitaxial thin films, which is associated with a large magnetoresistive effect allowing simple read-out.
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Affiliation(s)
- S Yu Bodnar
- Institut für Physik, Johannes Gutenberg-Universität, Staudinger Weg 7, 55128, Mainz, Germany
| | - L Šmejkal
- Institut für Physik, Johannes Gutenberg-Universität, Staudinger Weg 7, 55128, Mainz, Germany.,Institute of Physics, Academy of Sciences of the Czech Republic, Cukrovarnicka 10, 162 00, Praha 6, Czech Republic.,Department of Condensed Matter Physics, Faculty of Mathematics and Physics, Charles University, Ke Karlovu 5, 12116, Praha 2, Czech Republic
| | - I Turek
- Department of Condensed Matter Physics, Faculty of Mathematics and Physics, Charles University, Ke Karlovu 5, 12116, Praha 2, Czech Republic
| | - T Jungwirth
- Institute of Physics, Academy of Sciences of the Czech Republic, Cukrovarnicka 10, 162 00, Praha 6, Czech Republic.,School of Physics and Astronomy, University of Nottingham, University Park, Nottingham, NG7 2RD, UK
| | - O Gomonay
- Institut für Physik, Johannes Gutenberg-Universität, Staudinger Weg 7, 55128, Mainz, Germany
| | - J Sinova
- Institut für Physik, Johannes Gutenberg-Universität, Staudinger Weg 7, 55128, Mainz, Germany
| | - A A Sapozhnik
- Institut für Physik, Johannes Gutenberg-Universität, Staudinger Weg 7, 55128, Mainz, Germany
| | - H-J Elmers
- Institut für Physik, Johannes Gutenberg-Universität, Staudinger Weg 7, 55128, Mainz, Germany
| | - M Kläui
- Institut für Physik, Johannes Gutenberg-Universität, Staudinger Weg 7, 55128, Mainz, Germany
| | - M Jourdan
- Institut für Physik, Johannes Gutenberg-Universität, Staudinger Weg 7, 55128, Mainz, Germany.
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10
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Abstract
Spin-orbit-related effects offer a highly promising route for reading and writing information in magnetic units of future devices. These phenomena rely not only on the static magnetization orientation but also on its dynamics to achieve fast switchings that can reach the THz range. In this work, we consider Co/Pt and Fe/W bilayers to show that accounting for the phase difference between different processes is crucial to the correct description of the dynamical currents. By tuning each system towards its ferromagnetic resonance, we reveal that dynamical spin Hall angles can non-trivially change sign and be boosted by over 500%, reaching giant values. We demonstrate that charge and spin pumping mechanisms can greatly magnify or dwindle the currents flowing through the system, influencing all kinds of magnetoresistive and Hall effects, thus impacting also dc and second harmonic experimental measurements.
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11
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Scharf B, Matos-Abiague A, Han JE, Hankiewicz EM, Žutić I. Tunneling Planar Hall Effect in Topological Insulators: Spin Valves and Amplifiers. PHYSICAL REVIEW LETTERS 2016; 117:166806. [PMID: 27792378 DOI: 10.1103/physrevlett.117.166806] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 12/29/2015] [Indexed: 06/06/2023]
Abstract
We investigate tunneling across a single ferromagnetic barrier on the surface of a three-dimensional topological insulator. In the presence of a magnetization component along the bias direction, a tunneling planar Hall conductance (TPHC), transverse to the applied bias, develops. Electrostatic control of the barrier enables a giant Hall angle, with the TPHC exceeding the longitudinal tunneling conductance. By changing the in-plane magnetization direction, it is possible to change the sign of both the longitudinal and transverse differential conductance without opening a gap in the topological surface state. The transport in a topological-insulator-ferromagnet junction can, thus, be drastically altered from a simple spin valve to an amplifier.
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Affiliation(s)
- Benedikt Scharf
- Department of Physics, University at Buffalo, State University of New York, Buffalo, New York 14260, USA
| | - Alex Matos-Abiague
- Department of Physics, University at Buffalo, State University of New York, Buffalo, New York 14260, USA
| | - Jong E Han
- Department of Physics, University at Buffalo, State University of New York, Buffalo, New York 14260, USA
| | - Ewelina M Hankiewicz
- Institute for Theoretical Physics and Astrophysics, University of Würzburg, Am Hubland, 97074 Würzburg, Germany
| | - Igor Žutić
- Department of Physics, University at Buffalo, State University of New York, Buffalo, New York 14260, USA
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12
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Mokrousov Y, Zhang H, Freimuth F, Zimmermann B, Long NH, Weischenberg J, Souza I, Mavropoulos P, Blügel S. Anisotropy of spin relaxation and transverse transport in metals. JOURNAL OF PHYSICS. CONDENSED MATTER : AN INSTITUTE OF PHYSICS JOURNAL 2013; 25:163201. [PMID: 23511040 DOI: 10.1088/0953-8984/25/16/163201] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/01/2023]
Abstract
Using first-principles methods we explore the anisotropy of the spin relaxation and transverse transport properties in bulk metals with respect to the real-space direction of the spin-quantization axis in paramagnets or of the spontaneous magnetization in ferromagnets. Owing to the presence of the spin-orbit coupling the orbital and spin character of the Bloch states depends sensitively on the orientation of the spins relative to the crystal axes. This leads to drastic changes in quantities which rely on interband mixing induced by the spin-orbit interaction. The anisotropy is particularly striking for quantities which exhibit spiky and irregular distributions in the Brillouin zone, such as the spin-mixing parameter or the Berry curvature of the electronic states. We demonstrate this for three cases: (i) the Elliott-Yafet spin-relaxation mechanism in paramagnets with structural inversion symmetry; (ii) the intrinsic anomalous Hall effect in ferromagnets; and (iii) the spin Hall effect in paramagnets. We discuss the consequences of the pronounced anisotropic behavior displayed by these properties for spin-polarized transport applications.
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Affiliation(s)
- Yuriy Mokrousov
- Peter Grünberg Institut and Institute for Advanced Simulation, Forschungszentrum Jülich and JARA, Jülich, Germany.
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