1
|
Ai W, Chen F, Liu Z, Yuan X, Zhang L, He Y, Dong X, Fu H, Luo F, Deng M, Wang R, Wu J. Observation of giant room-temperature anisotropic magnetoresistance in the topological insulator β-Ag 2Te. Nat Commun 2024; 15:1259. [PMID: 38341422 DOI: 10.1038/s41467-024-45643-y] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/13/2023] [Accepted: 01/29/2024] [Indexed: 02/12/2024] Open
Abstract
Achieving room-temperature high anisotropic magnetoresistance ratios is highly desirable for magnetic sensors with scaled supply voltages and high sensitivities. However, the ratios in heterojunction-free thin films are currently limited to only a few percent at room temperature. Here, we observe a high anisotropic magnetoresistance ratio of -39% and a giant planar Hall effect (520 μΩ⋅cm) at room temperature under 9 T in β-Ag2Te crystals grown by chemical vapor deposition. We propose a theoretical model of anisotropic scattering - induced by a Dirac cone tilt and modulated by intrinsic properties of effective mass and sound velocity - as a possible origin. Moreover, small-size angle sensors with a Wheatstone bridge configuration were fabricated using the synthesized β-Ag2Te crystals. The sensors exhibited high output response (240 mV/V), high angle sensitivity (4.2 mV/V/°) and small angle error (<1°). Our work translates the developments in topological insulators to a broader impact on practical applications such as high-field magnetic and angle sensors.
Collapse
Affiliation(s)
- Wei Ai
- Tianjin Key Lab for Rare Earth Materials and Applications, Center for Rare Earth and Inorganic Functional Materials, Smart Sensor Interdisciplinary Science Center, School of Materials Science and Engineering, Nankai University, Tianjin, 300350, China
| | - Fuyang Chen
- Guangdong Provincial Key Laboratory of Quantum Engineering and Quantum Materials, School of Physics, South China Normal University, Guangzhou, 510006, China
| | - Zhaochao Liu
- Tianjin Key Lab for Rare Earth Materials and Applications, Center for Rare Earth and Inorganic Functional Materials, Smart Sensor Interdisciplinary Science Center, School of Materials Science and Engineering, Nankai University, Tianjin, 300350, China
| | - Xixi Yuan
- Center of Quantum Materials and Devices & College of Physics, Chongqing University, Chongqing, 401331, China
| | - Lei Zhang
- Tianjin Key Lab for Rare Earth Materials and Applications, Center for Rare Earth and Inorganic Functional Materials, Smart Sensor Interdisciplinary Science Center, School of Materials Science and Engineering, Nankai University, Tianjin, 300350, China
| | - Yuyu He
- Tianjin Key Lab for Rare Earth Materials and Applications, Center for Rare Earth and Inorganic Functional Materials, Smart Sensor Interdisciplinary Science Center, School of Materials Science and Engineering, Nankai University, Tianjin, 300350, China
| | - Xinyue Dong
- Tianjin Key Lab for Rare Earth Materials and Applications, Center for Rare Earth and Inorganic Functional Materials, Smart Sensor Interdisciplinary Science Center, School of Materials Science and Engineering, Nankai University, Tianjin, 300350, China
| | - Huixia Fu
- Center of Quantum Materials and Devices & College of Physics, Chongqing University, Chongqing, 401331, China.
| | - Feng Luo
- Tianjin Key Lab for Rare Earth Materials and Applications, Center for Rare Earth and Inorganic Functional Materials, Smart Sensor Interdisciplinary Science Center, School of Materials Science and Engineering, Nankai University, Tianjin, 300350, China.
| | - Mingxun Deng
- Guangdong Provincial Key Laboratory of Quantum Engineering and Quantum Materials, School of Physics, South China Normal University, Guangzhou, 510006, China.
| | - Ruiqiang Wang
- Guangdong Provincial Key Laboratory of Quantum Engineering and Quantum Materials, School of Physics, South China Normal University, Guangzhou, 510006, China
| | - Jinxiong Wu
- Tianjin Key Lab for Rare Earth Materials and Applications, Center for Rare Earth and Inorganic Functional Materials, Smart Sensor Interdisciplinary Science Center, School of Materials Science and Engineering, Nankai University, Tianjin, 300350, China.
| |
Collapse
|
2
|
Du Y, Zhao Y, Wang L, He Z, Wu Y, Wang C, Zhao L, Jiang Z, Liu M, Zhou Z. Deterministic Magnetization Reversal in Synthetic Antiferromagnets using Natural Light. SMALL (WEINHEIM AN DER BERGSTRASSE, GERMANY) 2023; 19:e2302884. [PMID: 37403297 DOI: 10.1002/smll.202302884] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 04/06/2023] [Revised: 05/31/2023] [Indexed: 07/06/2023]
Abstract
Traditional current-driven spintronics is limited by localized heating issues and large energy consumption, restricting their data storage density and operation speed. Meanwhile, voltage-driven spintronics with much lower energy dissipation also suffers from charge-induced interfacial corrosion. Thereby finding a novel way of tuning ferromagnetism is crucial for spintronics with energy-saving and good reliability. Here, a visible light tuning of interfacial exchange interaction via photoelectron doping into synthetic antiferromagnetic heterostructure of CoFeB/Cu/CoFeB/PN Si substrate is demonstrated. Then, a complete, reversible magnetism switching between antiferromagnetic (AFM) and ferromagnetic (FM) states with visible light on and off is realized. Moreover, a visible light control of 180° deterministic magnetization switching with a tiny magnetic bias field is achieved. The magnetic optical Kerr effect results further reveal the magnetic domain switching pathway between AFM and FM domains. The first-principle calculations conclude that the photoelectrons fill in the unoccupied band and raise the Fermi energy, which increases the exchange interaction. Lastly, a prototype device with visible light control of two states switching with a 0.35% giant magnetoresistance ratio change (maximal 0.4%), paving the way toward fast, compact, and energy-efficient solar-driven memories is fabricated.
Collapse
Affiliation(s)
- Yujing Du
- Electronic Materials Research Laboratory, Key Laboratory of the Ministry of Education & International Center for Dielectric Research, School of Electronic Science and Engineering, State Key Laboratory for Manufacturing Systems Engineering, The International Joint Laboratory for Micro/Nano Manufacturing and Measurement Technology, Xi'an Jiaotong University, Xi'an, 710049, China
| | - Yifan Zhao
- Electronic Materials Research Laboratory, Key Laboratory of the Ministry of Education & International Center for Dielectric Research, School of Electronic Science and Engineering, State Key Laboratory for Manufacturing Systems Engineering, The International Joint Laboratory for Micro/Nano Manufacturing and Measurement Technology, Xi'an Jiaotong University, Xi'an, 710049, China
| | - Lei Wang
- Center for Spintronics and Quantum Systems, State Key Laboratory for Mechanical Behavior of Materials, Xi'an Jiaotong University, No. 28 Xianning West Road Xi'an, Shaanxi, 710049, China
| | - Zhexi He
- Electronic Materials Research Laboratory, Key Laboratory of the Ministry of Education & International Center for Dielectric Research, School of Electronic Science and Engineering, State Key Laboratory for Manufacturing Systems Engineering, The International Joint Laboratory for Micro/Nano Manufacturing and Measurement Technology, Xi'an Jiaotong University, Xi'an, 710049, China
| | - Yangyang Wu
- School of Mathematical Sciences, Tiangong University, Tianjin, 300387, China
| | - Chenying Wang
- State Key Laboratory for Manufacturing Systems Engineering, Collaborative Innovation Center of High-End Manufacturing Equipment, The International Joint Laboratory for Micro/Nano Manufacturing and Measurement Technology, Xi'an Jiaotong University, Xi'an, 710049, China
| | - Libo Zhao
- State Key Laboratory for Manufacturing Systems Engineering, Collaborative Innovation Center of High-End Manufacturing Equipment, The International Joint Laboratory for Micro/Nano Manufacturing and Measurement Technology, Xi'an Jiaotong University, Xi'an, 710049, China
| | - Zhuangde Jiang
- State Key Laboratory for Manufacturing Systems Engineering, Collaborative Innovation Center of High-End Manufacturing Equipment, The International Joint Laboratory for Micro/Nano Manufacturing and Measurement Technology, Xi'an Jiaotong University, Xi'an, 710049, China
| | - Ming Liu
- Electronic Materials Research Laboratory, Key Laboratory of the Ministry of Education & International Center for Dielectric Research, School of Electronic Science and Engineering, State Key Laboratory for Manufacturing Systems Engineering, The International Joint Laboratory for Micro/Nano Manufacturing and Measurement Technology, Xi'an Jiaotong University, Xi'an, 710049, China
| | - Ziyao Zhou
- Electronic Materials Research Laboratory, Key Laboratory of the Ministry of Education & International Center for Dielectric Research, School of Electronic Science and Engineering, State Key Laboratory for Manufacturing Systems Engineering, The International Joint Laboratory for Micro/Nano Manufacturing and Measurement Technology, Xi'an Jiaotong University, Xi'an, 710049, China
| |
Collapse
|
3
|
Ritzinger P, Výborný K. Anisotropic magnetoresistance: materials, models and applications. ROYAL SOCIETY OPEN SCIENCE 2023; 10:230564. [PMID: 37859834 PMCID: PMC10582618 DOI: 10.1098/rsos.230564] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 04/28/2023] [Accepted: 09/07/2023] [Indexed: 10/21/2023]
Abstract
Resistance of certain (conductive and otherwise isotropic) ferromagnets turns out to exhibit anisotropy with respect to the direction of magnetization: R ∥ for magnetization parallel to the electric current direction is different from R⊥ for magnetization perpendicular to the electric current direction. In this review, this century-old phenomenon is reviewed both from the perspective of materials and physical mechanisms involved. More recently, this effect has also been identified and studied in antiferromagnets. To date, sensors based on the anisotropic magnetoresistance (AMR) effect are widely used in different fields, such as the automotive industry, aerospace or in biomedical imaging.
Collapse
Affiliation(s)
- Philipp Ritzinger
- FZU—Institute of Physics, Academy of Sciences of the Czech Republic, Cukrovarnická 10, Praha 6 16253, Czech Republic
- MFF—Faculty of Mathematics and Physics, Charles University, Ke Karlovu 5, Praha 2 12000, Czech Republic
| | - Karel Výborný
- FZU—Institute of Physics, Academy of Sciences of the Czech Republic, Cukrovarnická 10, Praha 6 16253, Czech Republic
| |
Collapse
|
4
|
Jun AH, Hwang YH, Kang B, Lee S, Seok J, Lee JS, Song SH, Ju BK. Magnetic Properties of Amorphous Ta/CoFeB/MgO/Ta Thin Films on Deformable Substrates with Magnetic Field Angle and Tensile Strain. SENSORS (BASEL, SWITZERLAND) 2023; 23:7479. [PMID: 37687934 PMCID: PMC10490707 DOI: 10.3390/s23177479] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 06/19/2023] [Revised: 07/09/2023] [Accepted: 07/18/2023] [Indexed: 09/10/2023]
Abstract
Recently, the application of cobalt iron boron (CoFeB) thin films in magnetic sensors has been widely studied owing to their high magnetic moment, anisotropy, and stability. However, most of these studies were conducted on rigid silicon substrates. For diverse applications of magnetic and angle sensors, it is important to explore the properties of ferromagnetic thin films grown on nonrigid deformable substrates. In this study, representative deformable substrates (polyimide (PI), polyethylene naphthalate (PEN), and polydimethylsiloxane (PDMS)), which can be bent or stretched, were used to assess the in-plane magnetic field angle-dependent properties of amorphous Ta/CoFeB/MgO/Ta thin films grown on deformable substrates. The effects of substrate roughness, tensile stress, deformable substrate characteristics, and sputtering on magnetic properties, such as the coercive field (Hc), remanence over saturation magnetization (Mr/Ms), and biaxial characteristics, were investigated. This study presents an unconventional foundation for exploring deformable magnetic sensors capable of detecting magnetic field angles.
Collapse
Affiliation(s)
| | | | | | | | | | | | | | - Byeong-Kwon Ju
- Display and Nanosensor Laboratory, School of Electrical Engineering, Korea University, 145, Anam-ro, Seongbuk-gu, Seoul 02841, Republic of Korea (Y.H.H.)
| |
Collapse
|
5
|
Wang Z, Zheng Y, Chen J, Wang Y, Liang Y, Li X, Wu F. Room-temperature half-metals induced via chemical surface modification: 2D Mn 2Se 2 monolayer. Phys Chem Chem Phys 2023; 25:14294-14302. [PMID: 37183440 DOI: 10.1039/d3cp00922j] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 05/16/2023]
Abstract
Compared with various antiferromagnetic (AFM) materials, two-dimensional (2D) room-temperature ferromagnetic (FM) materials are rarely discovered because of the geometrically determined spin interactions. Since 2D FM materials have shown great potential in the next-generational information devices, it is quite important to design new FM materials based on the reported AFM materials. Here, in this study, we found that the Mn2Se2 monolayer can be converted to half-metal from AFM semiconductor at room temperature by edge modification of certain chemical groups (such as -Cl, -Br, -I, and -S) based on systematical first-principles calculations. Our results show that the adsorbed chemical groups significantly modify the electronic states of Mn ions and the resulting spin interactions. Moreover, our results indicate that the Curie temperatures (Tc) of some Mn2Se2 monolayer derivatives approach or even exceed room temperature, among which Curie temperatures after chemical modification by -Cl, -Br, -I, -S are 290 K, 320 K, 400 K, and 1050 K, respectively. Thus, chemical modifications can be one of the effective methods to construct 2D FM materials in experiments.
Collapse
Affiliation(s)
- Zhe Wang
- College of Information Science and Technology, Nanjing Forestry University, Nanjing, Jiangsu 210037, P. R. China.
| | - Yanqiu Zheng
- College of Information Science and Technology, Nanjing Forestry University, Nanjing, Jiangsu 210037, P. R. China.
| | - Ji Chen
- College of Information Science and Technology, Nanjing Forestry University, Nanjing, Jiangsu 210037, P. R. China.
| | - Yun Wang
- College of Information Science and Technology, Nanjing Forestry University, Nanjing, Jiangsu 210037, P. R. China.
| | - Yu Liang
- College of Information Science and Technology, Nanjing Forestry University, Nanjing, Jiangsu 210037, P. R. China.
| | - Xiang Li
- College of Information Science and Technology, Nanjing Forestry University, Nanjing, Jiangsu 210037, P. R. China.
| | - Fang Wu
- College of Information Science and Technology, Nanjing Forestry University, Nanjing, Jiangsu 210037, P. R. China.
| |
Collapse
|
6
|
Huang X, Jiang S, Wu B, Huo R, Zhao X, Xing G, Long S, Gao N. Magnetically tunable diffractive optical elements based on ion-irradiated ultrathin ferromagnetic stacks. OPTICS LETTERS 2023; 48:2305-2308. [PMID: 37126260 DOI: 10.1364/ol.486633] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/03/2023]
Abstract
We report a novel type of magnetically tunable diffractive optical element (DOE) based on ultrathin ferromagnetic (FM) Pt/Co stacks. The Pt/Co stacks are irradiated by Ar+ ions at selected areas so that the perpendicular anisotropy is spatially modulated and the DOEs can be tuned by an external magnetic field through the magnetooptical effect. Based on this concept, a diffraction grating and a Fresnel zone plate (FZP) were developed, and complementary experimental results corroborate that a magnetic field can simultaneously manipulate both the zeroth and the first diffraction orders of these DOEs. Importantly, this effect can be utilized to enhance or hide the image formed by the FZP. Our studies pave the way toward developing compact and high-precision DOEs with fast and robust tunability, facilitating various applications spanning a wide spectrum range.
Collapse
|
7
|
Spin-flip-driven anomalous Hall effect and anisotropic magnetoresistance in a layered Ising antiferromagnet. Sci Rep 2023; 13:3391. [PMID: 36854958 PMCID: PMC9974960 DOI: 10.1038/s41598-023-30076-2] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/29/2022] [Accepted: 02/15/2023] [Indexed: 03/02/2023] Open
Abstract
The influence of magnetocrystalline anisotropy in antiferromagnets is evident in a spin flip or flop transition. Contrary to spin flops, a spin-flip transition has been scarcely presented due to its specific condition of relatively strong magnetocrystalline anisotropy and the role of spin-flips on anisotropic phenomena has not been investigated in detail. In this study, we present antiferromagnet-based functional properties on an itinerant Ising antiferromagnet Ca0.9Sr0.1Co2As2. In the presence of a rotating magnetic field, anomalous Hall conductivity and anisotropic magnetoresistance are demonstrated, the effects of which are maximized above the spin-flip transition. Moreover, a joint experimental and theoretical study is conducted to provide an efficient tool to identify various spin states, which can be useful in spin-processing functionalities.
Collapse
|
8
|
Zhang JX, Wang CM. A 2 π-periodic anisotropic magnetoresistance in multi-Weyl semimetals. JOURNAL OF PHYSICS. CONDENSED MATTER : AN INSTITUTE OF PHYSICS JOURNAL 2023; 35:125301. [PMID: 36652717 DOI: 10.1088/1361-648x/acb47a] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 10/05/2022] [Accepted: 01/18/2023] [Indexed: 06/17/2023]
Abstract
A 2π-periodic anisotropic magnetoresistance (AMR) violating the classical two-fold symmetry is found in the multi-Weyl semimetals. It is induced by the intrinsic magnetization due to the magnetic doping. The monopole charge influences the novel AMR, strongly. For single- and triple-Weyl semimetals, tilt along thex-direction or equivalently along they-direction is indispensable in the nonzero AMR. However, the AMR with 2πperiod even exists for the untilted double-Weyl case. The oscillation of the conductivity for the triple one is out-of-phase compared to the other two. We decompose the conductivity into theπand 2πparts. The amplitude of the dominant 2πcontribution increases almost linearly with the magnetization for all three cases. Moreover, the strength of the magnetic scattering strongly affects the magnitudes. Our work will contribute to a deeper understanding of the AMR in multi-Weyl semimetals.
Collapse
Affiliation(s)
- J X Zhang
- Department of Physics, Shanghai Normal University, Shanghai 200234, People's Republic of China
| | - C M Wang
- Department of Physics, Shanghai Normal University, Shanghai 200234, People's Republic of China
| |
Collapse
|
9
|
Pandey S, Zhang H, Yang J, May AF, Sanchez JJ, Liu Z, Chu JH, Kim JW, Ryan PJ, Zhou H, Liu J. Controllable Emergent Spatial Spin Modulation in Sr_{2}IrO_{4} by In Situ Shear Strain. PHYSICAL REVIEW LETTERS 2022; 129:027203. [PMID: 35867461 DOI: 10.1103/physrevlett.129.027203] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 01/27/2022] [Revised: 05/16/2022] [Accepted: 05/17/2022] [Indexed: 06/15/2023]
Abstract
Symmetric anisotropic interaction can be ferromagnetic and antiferromagnetic at the same time but for different crystallographic axes. We show that the competition of anisotropic interactions of orthogonal irreducible representations can be a general route to obtain new exotic magnetic states. We demonstrate it here by observing the emergence of a continuously tunable 12-layer spatial spin modulation when distorting the square-lattice planes in the quasi-two-dimensional antiferromagnetic Sr_{2}IrO_{4} under in situ shear strain. This translation-symmetry-breaking phase is a result of an unusual strain-activated anisotropic interaction which is at the fourth order and competing with the inherent quadratic anisotropic interaction. Such a mechanism of competing anisotropy is distinct from that among the ferromagnetic, antiferromagnetic, and/or the Dzyaloshinskii-Moriya interactions, and it could be widely applicable and highly controllable in low-dimensional magnets.
Collapse
Affiliation(s)
- Shashi Pandey
- Department of Physics and Astronomy, University of Tennessee, Knoxville, Tennessee 37996, USA
| | - Han Zhang
- Department of Physics and Astronomy, University of Tennessee, Knoxville, Tennessee 37996, USA
| | - Junyi Yang
- Department of Physics and Astronomy, University of Tennessee, Knoxville, Tennessee 37996, USA
| | - Andrew F May
- Materials Science and Technology Division, Oak Ridge National Laboratory, Oak Ridge, Tennessee 37831, USA
| | - Joshua J Sanchez
- Advanced Photon Source, Argonne National Laboratory, Argonne, Illinois 60439, USA
- Department of Physics, University of Washington, Seattle, Washington 98195, USA
| | - Zhaoyu Liu
- Department of Physics, University of Washington, Seattle, Washington 98195, USA
| | - Jiun-Haw Chu
- Department of Physics, University of Washington, Seattle, Washington 98195, USA
| | - Jong-Woo Kim
- Advanced Photon Source, Argonne National Laboratory, Argonne, Illinois 60439, USA
| | - Philip J Ryan
- Advanced Photon Source, Argonne National Laboratory, Argonne, Illinois 60439, USA
- School of Physical Sciences, Dublin City University, Dublin 11, Ireland
| | - Haidong Zhou
- Department of Physics and Astronomy, University of Tennessee, Knoxville, Tennessee 37996, USA
| | - Jian Liu
- Department of Physics and Astronomy, University of Tennessee, Knoxville, Tennessee 37996, USA
| |
Collapse
|
10
|
Zhu R, Gao Z, Liang Q, Hu J, Wang JS, Qiu CW, Wee ATS. Observation of Anisotropic Magnetoresistance in Layered Nonmagnetic Semiconducting PdSe 2. ACS APPLIED MATERIALS & INTERFACES 2021; 13:37527-37534. [PMID: 34333972 DOI: 10.1021/acsami.1c10500] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/13/2023]
Abstract
Anisotropy in crystals usually has remarkable consequences in two-dimensional (2D) materials, for example, black phosphorus, PdSe2, and SnS, arising from different lattice periodicities along different crystallographic directions. Electrical anisotropy has been successfully demonstrated in 2D materials, but anisotropic magnetoresistance in 2D materials is rarely studied. Herein, we report anisotropic magnetoresistance in layered nonmagnetic semiconducting PdSe2 flakes. Anisotropic magnetoresistance along the two crystalline axes under a perpendicular magnetic field is demonstrated, and the magnetoresistance along the a-axis is apparently different from the magnetoresistance along the b-axis. The magnetoresistance can also be flexibly tuned by applying a gate voltage, leveraging the semiconductor properties of PdSe2. The computed anisotropic electronic density of states and electronic mobility with ab initio density functional calculations support the anisotropic and measured magnetoresistance. Our findings advance the understanding of magnetoresistance in anisotropic transition-metal dichalcogenides and pave the way for potential applications in anisotropic spintronic devices.
Collapse
Affiliation(s)
- Rui Zhu
- Department of Physics, National University of Singapore, 2 Science Drive 3, Singapore 117551, Singapore
| | - Zhibin Gao
- Department of Physics, National University of Singapore, 2 Science Drive 3, Singapore 117551, Singapore
- State Key Laboratory for Mechanical Behavior of Materials, Xi'an Jiaotong University, Xi'an 710049, China
| | - Qijie Liang
- Department of Physics, National University of Singapore, 2 Science Drive 3, Singapore 117551, Singapore
- Songshan Lake Materials Laboratory, Songshan Lake Mat Lab, Dongguan 523808, China
| | - Junxiong Hu
- Department of Physics, National University of Singapore, 2 Science Drive 3, Singapore 117551, Singapore
| | - Jian-Sheng Wang
- Department of Physics, National University of Singapore, 2 Science Drive 3, Singapore 117551, Singapore
| | - Cheng-Wei Qiu
- Department of Electrical and Computer Engineering, National University of Singapore, 4 Engineering Drive 3, Singapore 117583, Singapore
| | - Andrew Thye Shen Wee
- Department of Physics, National University of Singapore, 2 Science Drive 3, Singapore 117551, Singapore
- Centre for Advanced 2D Materials and Graphene Research Centre, National University of Singapore, 6 Science Drive 2, Singapore 117546, Singapore
| |
Collapse
|
11
|
Seo J, An ES, Park T, Hwang SY, Kim GY, Song K, Noh WS, Kim JY, Choi GS, Choi M, Oh E, Watanabe K, Taniguchi T, Park JH, Jo YJ, Yeom HW, Choi SY, Shim JH, Kim JS. Tunable high-temperature itinerant antiferromagnetism in a van der Waals magnet. Nat Commun 2021; 12:2844. [PMID: 33990589 PMCID: PMC8121823 DOI: 10.1038/s41467-021-23122-y] [Citation(s) in RCA: 14] [Impact Index Per Article: 4.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/08/2020] [Accepted: 04/13/2021] [Indexed: 11/29/2022] Open
Abstract
Discovery of two dimensional (2D) magnets, showing intrinsic ferromagnetic (FM) or antiferromagnetic (AFM) orders, has accelerated development of novel 2D spintronics, in which all the key components are made of van der Waals (vdW) materials and their heterostructures. High-performing and energy-efficient spin functionalities have been proposed, often relying on current-driven manipulation and detection of the spin states. In this regard, metallic vdW magnets are expected to have several advantages over the widely-studied insulating counterparts, but have not been much explored due to the lack of suitable materials. Here, we report tunable itinerant ferro- and antiferromagnetism in Co-doped Fe4GeTe2 utilizing the vdW interlayer coupling, extremely sensitive to the material composition. This leads to high TN antiferromagnetism of TN ~ 226 K in a bulk and ~210 K in 8 nm-thick nanoflakes, together with tunable magnetic anisotropy. The resulting spin configurations and orientations are sensitively controlled by doping, magnetic field, and thickness, which are effectively read out by electrical conduction. These findings manifest strong merits of metallic vdW magnets as an active component of vdW spintronic applications. Metallic van der Waals magnets have considerable technological promise, due to their ability to be strongly coupled with electronic currents and integrated in two dimensional heterostructures. Here, Seo et al. demonstrate highly tunable itinerant antiferromagnetism in a van der Waals magnet.
Collapse
Affiliation(s)
- Junho Seo
- Center for Artificial Low Dimensional Electronic Systems, Institute for Basic Science (IBS), Pohang, Korea.,Department of Physics, Pohang University of Science and Technology (POSTECH), Pohang, Korea
| | - Eun Su An
- Center for Artificial Low Dimensional Electronic Systems, Institute for Basic Science (IBS), Pohang, Korea.,Department of Physics, Pohang University of Science and Technology (POSTECH), Pohang, Korea
| | - Taesu Park
- Department of Chemistry, Pohang University of Science and Technology (POSTECH), Pohang, Korea
| | - Soo-Yoon Hwang
- Department of Materials Science and Engineering, Pohang University of Science and Technology (POSTECH), Pohang, Korea
| | - Gi-Yeop Kim
- Department of Materials Science and Engineering, Pohang University of Science and Technology (POSTECH), Pohang, Korea
| | - Kyung Song
- Materials Modeling and Characterization Department, KIMS, Changwon, Korea
| | - Woo-Suk Noh
- MPPC-CPM, Max Planck POSTECH/Korea Research Initiative, Pohang, Korea
| | - J Y Kim
- Center for Artificial Low Dimensional Electronic Systems, Institute for Basic Science (IBS), Pohang, Korea
| | - Gyu Seung Choi
- Center for Artificial Low Dimensional Electronic Systems, Institute for Basic Science (IBS), Pohang, Korea.,Department of Physics, Pohang University of Science and Technology (POSTECH), Pohang, Korea
| | - Minhyuk Choi
- Center for Artificial Low Dimensional Electronic Systems, Institute for Basic Science (IBS), Pohang, Korea.,Department of Physics, Pohang University of Science and Technology (POSTECH), Pohang, Korea
| | - Eunseok Oh
- Center for Artificial Low Dimensional Electronic Systems, Institute for Basic Science (IBS), Pohang, Korea.,Department of Physics, Pohang University of Science and Technology (POSTECH), Pohang, Korea
| | - Kenji Watanabe
- Research Center for Functional Materials, National Institute for Materials Science, Tsukuba, Japan
| | - Takashi Taniguchi
- International Center for Materials Nanoarchitectonics, National Institute for Materials Science, Tsukuba, Japan
| | - J -H Park
- Department of Physics, Pohang University of Science and Technology (POSTECH), Pohang, Korea.,MPPC-CPM, Max Planck POSTECH/Korea Research Initiative, Pohang, Korea
| | - Youn Jung Jo
- Department of Physics, Kyungpook National University, Daegu, Korea
| | - Han Woong Yeom
- Center for Artificial Low Dimensional Electronic Systems, Institute for Basic Science (IBS), Pohang, Korea.,Department of Physics, Pohang University of Science and Technology (POSTECH), Pohang, Korea
| | - Si-Young Choi
- Department of Materials Science and Engineering, Pohang University of Science and Technology (POSTECH), Pohang, Korea.
| | - Ji Hoon Shim
- Department of Physics, Pohang University of Science and Technology (POSTECH), Pohang, Korea. .,Department of Chemistry, Pohang University of Science and Technology (POSTECH), Pohang, Korea.
| | - Jun Sung Kim
- Center for Artificial Low Dimensional Electronic Systems, Institute for Basic Science (IBS), Pohang, Korea. .,Department of Physics, Pohang University of Science and Technology (POSTECH), Pohang, Korea.
| |
Collapse
|
12
|
Widita R, Muhammady S, Prasetiyawati RD, Marlina R, Suryanegara L, Purnama B, Kurniadi R, Darma Y. Revisiting the Structural, Electronic, and Magnetic Properties of (LaO)MnAs: Effect of Hubbard Correction and Origin of Mott-Insulating Behavior. ACS OMEGA 2021; 6:4440-4447. [PMID: 33644556 PMCID: PMC7906576 DOI: 10.1021/acsomega.0c05889] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 12/03/2020] [Accepted: 01/28/2021] [Indexed: 05/28/2023]
Abstract
We study the structural, electronic, and magnetic properties of the antiferromagnetic-layered oxyarsenide (LaO)MnAs system from the first-principle calculation. The increasing Hubbard energy (U) in the Mn 3d orbital induces the increasing local-symmetry distortions (LSDs) in MnAs4 and OLa4 tetrahedra. The LSD in MnAs4 tetrahedra is possibly promoted by the second-order Jahn-Teller effect in the Mn 3d orbital. Furthermore, the increasing U also escalates the bandgap (E g) and the magnetic moment of Mn (μMn). The value of U = 1 eV is the most appropriate by considering the structural properties. This value leads to E g and μMn of 0.834 eV and 4.31 μB, respectively. The calculated μMn is lower than the theoretical value for the high-spin state of Mn 3d (5 μB) due to the hybridization between Mn 3d and As 4p states. However, d xy states are localized and show the weakest hybridization with valence As 4p states. The Mott-insulating behavior in the system is characterized by the E g transition between the valence and conduction d zx /d zy states. This work shows new physical insights for advanced functional device applications, such as spintronics.
Collapse
Affiliation(s)
- Rena Widita
- Department
of Physics, Faculty of Mathematics and Natural Sciences, Institut Teknologi Bandung, Ganesha 10, Bandung 40132, Indonesia
| | - Shibghatullah Muhammady
- Department
of Physics, Faculty of Mathematics and Natural Sciences, Institut Teknologi Bandung, Ganesha 10, Bandung 40132, Indonesia
| | - Rahma Dhani Prasetiyawati
- Department
of Physics, Faculty of Mathematics and Natural Sciences, Institut Teknologi Bandung, Ganesha 10, Bandung 40132, Indonesia
| | - Resti Marlina
- Research
Center for Biomaterials, Indonesian Institute
of Sciences, Jl. Raya Jakarta-Bogor KM 46 Cibinong, Bogor 16911, Indonesia
| | - Lisman Suryanegara
- Research
Center for Biomaterials, Indonesian Institute
of Sciences, Jl. Raya Jakarta-Bogor KM 46 Cibinong, Bogor 16911, Indonesia
| | - Budi Purnama
- Department
of Physics, Faculty of Mathematics and Natural Sciences, Universitas Sebelas Maret, Ir. Sutami 36, Surakarta 57126, Indonesia
| | - Rizal Kurniadi
- Department
of Physics, Faculty of Mathematics and Natural Sciences, Institut Teknologi Bandung, Ganesha 10, Bandung 40132, Indonesia
| | - Yudi Darma
- Department
of Physics, Faculty of Mathematics and Natural Sciences, Institut Teknologi Bandung, Ganesha 10, Bandung 40132, Indonesia
| |
Collapse
|
13
|
Zhang H, Hao L, Yang J, Mutch J, Liu Z, Huang Q, Noordhoek K, May AF, Chu JH, Kim JW, Ryan PJ, Zhou H, Liu J. Comprehensive Electrical Control of Metamagnetic Transition of a Quasi-2D Antiferromagnet by In Situ Anisotropic Strain. ADVANCED MATERIALS (DEERFIELD BEACH, FLA.) 2020; 32:e2002451. [PMID: 32697370 DOI: 10.1002/adma.202002451] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 04/09/2020] [Revised: 06/12/2020] [Indexed: 06/11/2023]
Abstract
Effective nonmagnetic control of the spin structure is at the forefront of the study for functional quantum materials. This study demonstrates that, by applying an anisotropic strain up to only 0.05%, the metamagnetic transition field of spin-orbit-coupled Mott insulator Sr2 IrO4 can be in situ modulated by almost 300%. Simultaneous measurements of resonant X-ray scattering and transport reveal that this drastic response originates from the complete strain-tuning of the transition between the spin-flop and spin-flip limits, and is always accompanied by large elastoconductance and magnetoconductance. This enables electrically controllable and electronically detectable metamagnetic switching, despite the antiferromagnetic insulating state. The obtained strain-magnetic field phase diagram reveals that C4 -symmetry-breaking anisotropy is introduced by strain via pseudospin-lattice coupling, directly demonstrating the pseudo-Jahn-Teller effect of spin-orbit-coupled complex oxides. The extracted coupling strength is much weaker than the superexchange interactions, yet crucial for the spontaneous symmetry-breaking, affording the remarkably efficient strain-control.
Collapse
Affiliation(s)
- Han Zhang
- Department of Physics and Astronomy, The University of Tennessee, 217A A. H. Nielsen Physics Building, Knoxville, TN, 37996, USA
| | - Lin Hao
- Department of Physics and Astronomy, The University of Tennessee, 217A A. H. Nielsen Physics Building, Knoxville, TN, 37996, USA
| | - Junyi Yang
- Department of Physics and Astronomy, The University of Tennessee, 217A A. H. Nielsen Physics Building, Knoxville, TN, 37996, USA
| | - Josh Mutch
- Department of Physics, University of Washington, Seattle, WA, 98195, USA
| | - Zhaoyu Liu
- Department of Physics, University of Washington, Seattle, WA, 98195, USA
| | - Qing Huang
- Department of Physics and Astronomy, The University of Tennessee, 217A A. H. Nielsen Physics Building, Knoxville, TN, 37996, USA
| | - Kyle Noordhoek
- Department of Physics and Astronomy, The University of Tennessee, 217A A. H. Nielsen Physics Building, Knoxville, TN, 37996, USA
| | - Andrew F May
- Materials Science and Technology Division, Oak Ridge National Laboratory, Oak Ridge, TN, 37831, USA
| | - Jiun-Haw Chu
- Department of Physics, University of Washington, Seattle, WA, 98195, USA
| | - Jong-Woo Kim
- Advanced Photon Source, Argonne National Laboratory, Argonne, IL, 60439, USA
| | - Philip J Ryan
- Advanced Photon Source, Argonne National Laboratory, Argonne, IL, 60439, USA
- School of Physical Sciences, Dublin City University, Dublin 11, Ireland
| | - Haidong Zhou
- Department of Physics and Astronomy, The University of Tennessee, 217A A. H. Nielsen Physics Building, Knoxville, TN, 37996, USA
| | - Jian Liu
- Department of Physics and Astronomy, The University of Tennessee, 217A A. H. Nielsen Physics Building, Knoxville, TN, 37996, USA
| |
Collapse
|
14
|
Liu H, Wang X, Wu J, Chen Y, Wan J, Wen R, Yang J, Liu Y, Song Z, Xie L. Vapor Deposition of Magnetic Van der Waals NiI 2 Crystals. ACS NANO 2020; 14:10544-10551. [PMID: 32806048 DOI: 10.1021/acsnano.0c04499] [Citation(s) in RCA: 22] [Impact Index Per Article: 5.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/26/2023]
Abstract
The recent discovery of van der Waals magnetic materials has attracted great attention in materials science and spintronics. The preparation of ultrathin magnetic layers down to atomic thickness is challenging and is mostly by mechanical exfoliation. Here, we report vapor deposition of magnetic van der Waals NiI2 crystals. Two-dimensional (2D) NiI2 flakes are grown on SiO2/Si substrates with a thickness of 5-40 nm and on hexagonal boron nitride (h-BN) down to monolayer thickness. Temperature-dependent Raman spectroscopy reveals robust magnetic phase transitions in the as-grown 2D NiI2 crystals down to trilayer. Electrical measurements show a semiconducting transport behavior with a high on/off ratio of 106 for the NiI2 flakes. Lastly, density functional theory calculation shows an intralayer ferromagnetic and interlayer antiferromagnetic ordering in 2D NiI2. This work provides a feasible approach to epitaxy 2D magnetic transition metal halides and also offers atomically thin materials for spintronic devices.
Collapse
Affiliation(s)
- Haining Liu
- CAS Key Laboratory of Standardization and Measurement for Nanotechnology, CAS Center for Excellence in Nanoscience, National Center for Nanoscience and Technology, Beijing 100190, China
- University of Chinese Academy of Sciences, Beijing 100049, China
- College of Chemistry and Pharmaceutical Engineering, Hebei University of Science and Technology, Shijiazhuang 050018, China
| | - Xinsheng Wang
- CAS Key Laboratory of Standardization and Measurement for Nanotechnology, CAS Center for Excellence in Nanoscience, National Center for Nanoscience and Technology, Beijing 100190, China
| | - Juanxia Wu
- CAS Key Laboratory of Standardization and Measurement for Nanotechnology, CAS Center for Excellence in Nanoscience, National Center for Nanoscience and Technology, Beijing 100190, China
| | - Yuansha Chen
- Beijing National Laboratory for Condensed Matter Physics & Institute of Physics, Chinese Academy of Sciences, Beijing 100190, China
| | - Jing Wan
- Key Laboratory of Molecular Nanostructure and Nanotechnology, Beijing National Laboratory for Molecular Sciences, CAS Research/Education Center for Excellence in Molecular Sciences, Institute of Chemistry, Chinese Academy of Sciences, Beijing 100190, China
| | - Rui Wen
- Key Laboratory of Molecular Nanostructure and Nanotechnology, Beijing National Laboratory for Molecular Sciences, CAS Research/Education Center for Excellence in Molecular Sciences, Institute of Chemistry, Chinese Academy of Sciences, Beijing 100190, China
| | - Jinbo Yang
- State Key Laboratory for Mesoscopic Physics and School of Physics, Peking University, Beijing 100871, China
| | - Ying Liu
- CAS Key Laboratory of Standardization and Measurement for Nanotechnology, CAS Center for Excellence in Nanoscience, National Center for Nanoscience and Technology, Beijing 100190, China
| | - Zhigang Song
- State Key Laboratory for Mesoscopic Physics and School of Physics, Peking University, Beijing 100871, China
| | - Liming Xie
- CAS Key Laboratory of Standardization and Measurement for Nanotechnology, CAS Center for Excellence in Nanoscience, National Center for Nanoscience and Technology, Beijing 100190, China
- University of Chinese Academy of Sciences, Beijing 100049, China
| |
Collapse
|
15
|
Groenendijk DJ, Manca N, de Bruijckere J, Monteiro AMRVL, Gaudenzi R, van der Zant HSJ, Caviglia AD. Anisotropic magnetoresistance in spin-orbit semimetal SrIrO 3. EUROPEAN PHYSICAL JOURNAL PLUS 2020; 135:627. [PMID: 32832318 PMCID: PMC7411514 DOI: 10.1140/epjp/s13360-020-00613-3] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 02/11/2020] [Accepted: 07/15/2020] [Indexed: 06/11/2023]
Abstract
SrIrO 3 , the three-dimensional member of the Ruddlesden-Popper iridates, is a paramagnetic semimetal characterised by a the delicate interplay between spin-orbit coupling and Coulomb repulsion. In this work, we study the anisotropic magnetoresistance (AMR) of SrIrO 3 thin films, which is closely linked to spin-orbit coupling and probes correlations between electronic transport, magnetic order and orbital states. We show that the low-temperature negative magnetoresistance is anisotropic with respect to the magnetic field orientation, and its angular dependence reveals the appearance of a fourfold symmetric component above a critical magnetic field. We show that this AMR component is of magnetocrystalline origin, and attribute the observed transition to a field-induced magnetic state in SrIrO 3 .
Collapse
Affiliation(s)
- Dirk J. Groenendijk
- Kavli Institute of Nanoscience, Delft University of Technology, Lorentzweg 1, 2628 CJ Delft, The Netherlands
| | - Nicola Manca
- Kavli Institute of Nanoscience, Delft University of Technology, Lorentzweg 1, 2628 CJ Delft, The Netherlands
| | - Joeri de Bruijckere
- Kavli Institute of Nanoscience, Delft University of Technology, Lorentzweg 1, 2628 CJ Delft, The Netherlands
| | | | - Rocco Gaudenzi
- Kavli Institute of Nanoscience, Delft University of Technology, Lorentzweg 1, 2628 CJ Delft, The Netherlands
| | - Herre S. J. van der Zant
- Kavli Institute of Nanoscience, Delft University of Technology, Lorentzweg 1, 2628 CJ Delft, The Netherlands
| | - Andrea D. Caviglia
- Kavli Institute of Nanoscience, Delft University of Technology, Lorentzweg 1, 2628 CJ Delft, The Netherlands
| |
Collapse
|
16
|
Lu C, Liu JM. The J eff = 1/2 Antiferromagnet Sr 2 IrO 4 : A Golden Avenue toward New Physics and Functions. ADVANCED MATERIALS (DEERFIELD BEACH, FLA.) 2020; 32:e1904508. [PMID: 31667943 DOI: 10.1002/adma.201904508] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/14/2019] [Revised: 09/12/2019] [Indexed: 06/10/2023]
Abstract
Iridates have been providing a fertile ground for studying emergent phases of matter that arise from the delicate interplay of various fundamental interactions with approximate energy scale. Among these highly focused quantum materials, the perovskite Sr2 IrO4 , which belongs to the Ruddlesden-Popper series, stands out and has been intensively addressed in the last decade, since it hosts a novel Jeff = 1/2 state that is a profound manifestation of strong spin-orbit coupling. Moreover, the Jeff = 1/2 state represents a rare example of iridates that is better understood both theoretically and experimentally. Here, Sr2 IrO4 is taken as an example to review the recent advances of the Jeff = 1/2 state in two aspects: materials fundamentals and functionality potentials. In the fundamentals part, the basic issues for the layered canted antiferromagnetic order of the Jeff = 1/2 magnetic moments in Sr2 IrO4 are illustrated, and then the progress of the antiferromagnetic order modulation through diverse routes is highlighted. Subsequently, for the functionality potentials, fascinating properties such as atomic-scale giant magnetoresistance, anisotropic magnetoresistance, and nonvolatile memory, are addressed. To conclude, prospective remarks and an outlook are given.
Collapse
Affiliation(s)
- Chengliang Lu
- School of Physics and Wuhan National High Magnetic Field Center, Huazhong University of Science and Technology, Wuhan, 430074, China
| | - Jun-Ming Liu
- Laboratory of Solid State Microstructures and Innovation Center of Advanced Microstructures, Nanjing University, Nanjing, 210093, China
- Guangdong Provincial Key Laboratory of Quantum Engineering and Quantum Materials and Institute for Advanced Materials, South China Normal University, Guangzhou, 510006, China
| |
Collapse
|
17
|
Vaidya P, Morley SA, van Tol J, Liu Y, Cheng R, Brataas A, Lederman D, del Barco E. Subterahertz spin pumping from an insulating antiferromagnet. Science 2020; 368:160-165. [DOI: 10.1126/science.aaz4247] [Citation(s) in RCA: 100] [Impact Index Per Article: 25.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/09/2019] [Accepted: 03/12/2020] [Indexed: 11/02/2022]
Affiliation(s)
- Priyanka Vaidya
- Department of Physics, University of Central Florida, Orlando, FL 32765, USA
| | - Sophie A. Morley
- Department of Physics, University of California Santa Cruz, Santa Cruz, CA 95064, USA
| | - Johan van Tol
- National High Magnetic Field Laboratory, Florida State University, Tallahassee, FL 32310, USA
| | - Yan Liu
- College of Sciences, Northeastern University, Shenyang, Liaoning, China
| | - Ran Cheng
- Department of Electrical and Computer Engineering and Department of Physics and Astronomy, University of California, Riverside, CA 92521, USA
| | - Arne Brataas
- Center for Quantum Spintronics, Department of Physics, Norwegian University of Science and Technology, NO-7491 Trondheim, Norway
| | - David Lederman
- Department of Physics, University of California Santa Cruz, Santa Cruz, CA 95064, USA
| | - Enrique del Barco
- Department of Physics, University of Central Florida, Orlando, FL 32765, USA
| |
Collapse
|
18
|
Hao L, Wang Z, Yang J, Meyers D, Sanchez J, Fabbris G, Choi Y, Kim JW, Haskel D, Ryan PJ, Barros K, Chu JH, Dean MPM, Batista CD, Liu J. Anomalous magnetoresistance due to longitudinal spin fluctuations in a J eff = 1/2 Mott semiconductor. Nat Commun 2019; 10:5301. [PMID: 31757946 PMCID: PMC6874576 DOI: 10.1038/s41467-019-13271-6] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/03/2019] [Accepted: 10/24/2019] [Indexed: 11/09/2022] Open
Abstract
As a hallmark of electronic correlation, spin-charge interplay underlies many emergent phenomena in doped Mott insulators, such as high-temperature superconductivity, whereas the half-filled parent state is usually electronically frozen with an antiferromagnetic order that resists external control. We report on the observation of a positive magnetoresistance that probes the staggered susceptibility of a pseudospin-half square-lattice Mott insulator built as an artificial SrIrO3/SrTiO3 superlattice. Its size is particularly large in the high-temperature insulating paramagnetic phase near the Néel transition. This magnetoresistance originates from a collective charge response to the large longitudinal spin fluctuations under a linear coupling between the external magnetic field and the staggered magnetization enabled by strong spin-orbit interaction. Our results demonstrate a magnetic control of the binding energy of the fluctuating particle-hole pairs in the Slater-Mott crossover regime analogous to the Bardeen-Cooper-Schrieffer-to-Bose-Einstein condensation crossover of ultracold-superfluids. Spin-charge interactions are at the core of electronic correlation phenomena in Mott insulators. Here, the authors observe a positive anomalous magnetoresistance in a SrIrO3/SrTiO3 superlattice, indicative of strong spin-charge fluctuations in this pseudospin-half square-lattice Mott insulator.
Collapse
Affiliation(s)
- Lin Hao
- Department of Physics and Astronomy, University of Tennessee, Knoxville, TN, 37996, USA
| | - Zhentao Wang
- Department of Physics and Astronomy, University of Tennessee, Knoxville, TN, 37996, USA
| | - Junyi Yang
- Department of Physics and Astronomy, University of Tennessee, Knoxville, TN, 37996, USA
| | - D Meyers
- Department of Condensed Matter Physics and Materials Science, Brookhaven National Laboratory, Upton, NY, 11973, USA
| | - Joshua Sanchez
- Department of Physics, University of Washington, Seattle, WA, 98105, USA
| | - Gilberto Fabbris
- Advanced Photon Source, Argonne National Laboratory, Argonne, IL, 60439, USA
| | - Yongseong Choi
- Advanced Photon Source, Argonne National Laboratory, Argonne, IL, 60439, USA
| | - Jong-Woo Kim
- Advanced Photon Source, Argonne National Laboratory, Argonne, IL, 60439, USA
| | - Daniel Haskel
- Advanced Photon Source, Argonne National Laboratory, Argonne, IL, 60439, USA
| | - Philip J Ryan
- Advanced Photon Source, Argonne National Laboratory, Argonne, IL, 60439, USA.,School of Physical Sciences, Dublin City University, Dublin 9, Ireland
| | - Kipton Barros
- Theoretical Division and CNLS, Los Alamos National Laboratory, Los Alamos, New Mexico, 87545, USA
| | - Jiun-Haw Chu
- Department of Physics, University of Washington, Seattle, WA, 98105, USA
| | - M P M Dean
- Department of Condensed Matter Physics and Materials Science, Brookhaven National Laboratory, Upton, NY, 11973, USA
| | - Cristian D Batista
- Department of Physics and Astronomy, University of Tennessee, Knoxville, TN, 37996, USA.,Quantum Condensed Matter Division and Shull-Wollan Center, Oak Ridge National Laboratory, Oak Ridge, TN, 37831, USA
| | - Jian Liu
- Department of Physics and Astronomy, University of Tennessee, Knoxville, TN, 37996, USA.
| |
Collapse
|
19
|
Hajiri T, Baldrati L, Lebrun R, Filianina M, Ross A, Tanahashi N, Kuroda M, Gan WL, Menteş TO, Genuzio F, Locatelli A, Asano H, Kläui M. Spin structure and spin Hall magnetoresistance of epitaxial thin films of the insulating non-collinear antiferromagnet SmFeO 3. JOURNAL OF PHYSICS. CONDENSED MATTER : AN INSTITUTE OF PHYSICS JOURNAL 2019; 31:445804. [PMID: 31392970 DOI: 10.1088/1361-648x/ab303c] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/10/2023]
Abstract
We report a combined study of imaging the antiferromagnetic (AFM) spin structure and measuring the spin Hall magnetoresistance (SMR) in epitaxial thin films of the insulating non-collinear antiferromagnet SmFeO3. X-ray magnetic linear dichroism photoemission electron microscopy measurements reveal that the AFM spins of the SmFeO3(1 1 0) align in the plane of the film. Angularly dependent magnetoresistance measurements show that SmFeO3/Ta bilayers exhibit a positive SMR, in contrast to the negative SMR expected in previously studied collinear AFMs. The SMR amplitude increases linearly with increasing external magnetic field at higher magnetic fields, suggesting that field-induced canting of the AFM spins plays an important role. In contrast, around the coercive field, no detectable SMR signal is observed, indicating that the SMR of the AFM and canting magnetization components cancel out. Below 50 K, the SMR amplitude increases sizably by a factor of two as compared to room temperature, which likely correlates with the long-range ordering of the Sm ions. Our results show that the SMR is a sensitive technique for non-equilibrium spin systems of non-collinear AFMs.
Collapse
Affiliation(s)
- T Hajiri
- Department of Materials Physics, Nagoya University, Nagoya 464-8603, Japan
| | | | | | | | | | | | | | | | | | | | | | | | | |
Collapse
|
20
|
Interfacial charge-transfer Mott state in iridate-nickelate superlattices. Proc Natl Acad Sci U S A 2019; 116:19863-19868. [PMID: 31527227 DOI: 10.1073/pnas.1907043116] [Citation(s) in RCA: 12] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/18/2022] Open
Abstract
We investigate [Formula: see text]/[Formula: see text] superlattices in which we observe a full electron transfer at the interface from Ir to Ni, triggering a massive structural and electronic reconstruction. Through experimental characterization and first-principles calculations, we determine that a large crystal field splitting from the distorted interfacial [Formula: see text] octahedra surprisingly dominates over the spin-orbit coupling and together with the Hund's coupling results in the high-spin (S = 1) configurations on both the Ir and Ni sites. This demonstrates the power of interfacial charge transfer in coupling lattice, charge, orbital, and spin degrees of freedom, opening fresh avenues of investigation of quantum states in oxide superlattices.
Collapse
|
21
|
Giant anisotropic magnetoresistance and nonvolatile memory in canted antiferromagnet Sr 2IrO 4. Nat Commun 2019; 10:2280. [PMID: 31123257 PMCID: PMC6533248 DOI: 10.1038/s41467-019-10299-6] [Citation(s) in RCA: 37] [Impact Index Per Article: 7.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/28/2018] [Accepted: 05/02/2019] [Indexed: 11/09/2022] Open
Abstract
Antiferromagnets have been generating intense interest in the spintronics community, owing to their intrinsic appealing properties like zero stray field and ultrafast spin dynamics. While the control of antiferromagnetic (AFM) orders has been realized by various means, applicably appreciated functionalities on the readout side of AFM-based devices are urgently desired. Here, we report the remarkably enhanced anisotropic magnetoresistance (AMR) as giant as ~160% in a simple resistor structure made of AFM Sr2IrO4 without auxiliary reference layer. The underlying mechanism for the giant AMR is an indispensable combination of atomic scale giant-MR-like effect and magnetocrystalline anisotropy energy, which was not accessed earlier. Furthermore, we demonstrate the bistable nonvolatile memory states that can be switched in-situ without the inconvenient heat-assisted procedure, and robustly preserved even at zero magnetic field, due to the modified interlayer coupling by 1% Ga-doping in Sr2IrO4. These findings represent a straightforward step toward the AFM spintronic devices.
Collapse
|
22
|
Lee N, Ko E, Choi HY, Hong YJ, Nauman M, Kang W, Choi HJ, Choi YJ, Jo Y. Antiferromagnet-Based Spintronic Functionality by Controlling Isospin Domains in a Layered Perovskite Iridate. ADVANCED MATERIALS (DEERFIELD BEACH, FLA.) 2018; 30:e1805564. [PMID: 30370684 DOI: 10.1002/adma.201805564] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 08/27/2018] [Revised: 10/09/2018] [Indexed: 06/08/2023]
Abstract
The novel electronic state of the canted antiferromagnetic (AFM) insulator strontium iridate (Sr2 IrO4 ) is well described by the spin-orbit-entangled isospin Jeff = 1/2, but the role of isospin in transport phenomena remains poorly understood. In this study, antiferromagnet-based spintronic functionality is demonstrated by combining the unique characteristics of the isospin state in Sr2 IrO4 . Based on magnetic and transport measurements, a large and highly anisotropic magnetoresistance (AMR) is obtained by manipulating the AFM isospin domains. First-principles calculations suggest that electrons whose isospin directions are strongly coupled to the in-plane net magnetic moment encounter an isospin mismatch when moving across the AFM domain boundaries, which generates a high resistance state. By rotating a magnetic field that aligns in-plane net moments and removes domain boundaries, the macroscopically ordered isospins govern dynamic transport through the system, which leads to the extremely angle-sensitive AMR. As this work establishes a link between isospins and magnetotransport in strongly spin-orbit-coupled AFM Sr2 IrO4 , the peculiar AMR effect provides a beneficial foundation for fundamental and applied research on AFM spintronics.
Collapse
Affiliation(s)
- Nara Lee
- Department of Physics, Yonsei University, Seoul, 03722, Korea
| | - Eunjung Ko
- Department of Physics, Yonsei University, Seoul, 03722, Korea
| | - Hwan Young Choi
- Department of Physics, Yonsei University, Seoul, 03722, Korea
| | - Yun Jeong Hong
- Department of Physics, Kyungpook National University, Daegu, 41566, Korea
| | - Muhammad Nauman
- Department of Physics, Kyungpook National University, Daegu, 41566, Korea
| | - Woun Kang
- Department of Physics, Ewha Womans University, Seoul, 03760, Korea
| | | | - Young Jai Choi
- Department of Physics, Yonsei University, Seoul, 03722, Korea
| | - Younjung Jo
- Department of Physics, Kyungpook National University, Daegu, 41566, Korea
| |
Collapse
|
23
|
Song C, You Y, Chen X, Zhou X, Wang Y, Pan F. How to manipulate magnetic states of antiferromagnets. NANOTECHNOLOGY 2018; 29:112001. [PMID: 29337295 DOI: 10.1088/1361-6528/aaa812] [Citation(s) in RCA: 21] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/07/2023]
Abstract
Antiferromagnetic materials, which have drawn considerable attention recently, have fascinating features: they are robust against perturbation, produce no stray fields, and exhibit ultrafast dynamics. Discerning how to efficiently manipulate the magnetic state of an antiferromagnet is key to the development of antiferromagnetic spintronics. In this review, we introduce four main methods (magnetic, strain, electrical, and optical) to mediate the magnetic states and elaborate on intrinsic origins of different antiferromagnetic materials. Magnetic control includes a strong magnetic field, exchange bias, and field cooling, which are traditional and basic. Strain control involves the magnetic anisotropy effect or metamagnetic transition. Electrical control can be divided into two parts, electric field and electric current, both of which are convenient for practical applications. Optical control includes thermal and electronic excitation, an inertia-driven mechanism, and terahertz laser control, with the potential for ultrafast antiferromagnetic manipulation. This review sheds light on effective usage of antiferromagnets and provides a new perspective on antiferromagnetic spintronics.
Collapse
Affiliation(s)
- Cheng Song
- Key Laboratory of Advanced Materials (MOE), School of Materials Science and Engineering, Tsinghua University, Beijing 100084, People's Republic of China. Beijing Innovation Center for Future Chip, Tsinghua University, Beijing 100084, People's Republic of China
| | | | | | | | | | | |
Collapse
|
24
|
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.
Collapse
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.
| |
Collapse
|
25
|
Yi D, Lu N, Chen X, Shen S, Yu P. Engineering magnetism at functional oxides interfaces: manganites and beyond. JOURNAL OF PHYSICS. CONDENSED MATTER : AN INSTITUTE OF PHYSICS JOURNAL 2017; 29:443004. [PMID: 28745614 DOI: 10.1088/1361-648x/aa824d] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/07/2023]
Abstract
The family of transition metal oxides (TMOs) is a large class of magnetic materials that has been intensively studied due to the rich physics involved as well as the promising potential applications in next generation electronic devices. In TMOs, the spin, charge, orbital and lattice are strongly coupled, and significant advances have been achieved to engineer the magnetism by different routes that manipulate these degrees of freedom. The family of manganites is a model system of strongly correlated magnetic TMOs. In this review, using manganites thin films and the heterostructures in conjunction with other TMOs as model systems, we review the recent progress of engineering magnetism in TMOs. We first discuss the role of the lattice that includes the epitaxial strain and the interface structural coupling. Then we look into the role of charge, focusing on the interface charge modulation. Having demonstrated the static effects, we continue to review the research on dynamical control of magnetism by electric field. Next, we review recent advances in heterostructures comprised of high T c cuprate superconductors and manganites. Following that, we discuss the emergent magnetic phenomena at interfaces between 3d TMOs and 5d TMOs with strong spin-orbit coupling. Finally, we provide our outlook for prospective future directions.
Collapse
Affiliation(s)
- Di Yi
- Geballe Laboratory for Advanced Materials and Applied Physics Department, Stanford University, Stanford, CA 94305, United States of America
| | | | | | | | | |
Collapse
|
26
|
Železný J, Zhang Y, Felser C, Yan B. Spin-Polarized Current in Noncollinear Antiferromagnets. PHYSICAL REVIEW LETTERS 2017; 119:187204. [PMID: 29219584 DOI: 10.1103/physrevlett.119.187204] [Citation(s) in RCA: 46] [Impact Index Per Article: 6.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 02/01/2017] [Indexed: 06/07/2023]
Abstract
Noncollinear antiferromagnets, such as Mn_{3}Sn and Mn_{3}Ir, were recently shown to be analogous to ferromagnets in that they have a large anomalous Hall effect. Here we show that these materials are similar to ferromagnets in another aspect: the charge current in these materials is spin polarized. In addition, we show that the same mechanism that leads to the spin-polarized current also leads to a transverse spin current, which has a distinct symmetry and origin from the conventional spin Hall effect. We illustrate the existence of the spin-polarized current and the transverse spin current by performing ab initio microscopic calculations and by analyzing the symmetry. We discuss possible applications of these novel spin currents, such as an antiferromagnetic metallic or tunneling junction.
Collapse
Affiliation(s)
- Jakub Železný
- Max Planck Institute for Chemical Physics of Solids, 01187 Dresden, Germany
- Institute of Physics ASCR, 162 53 Praha 6, Czech Republic
| | - Yang Zhang
- Max Planck Institute for Chemical Physics of Solids, 01187 Dresden, Germany
- Leibniz Institute for Solid State and Materials Research, 01069 Dresden, Germany
| | - Claudia Felser
- Max Planck Institute for Chemical Physics of Solids, 01187 Dresden, Germany
| | - Binghai Yan
- Max Planck Institute for Chemical Physics of Solids, 01187 Dresden, Germany
- Department of Condensed Matter Physics, Weizmann Institute of Science, 7610001 Rehovot, Israel
| |
Collapse
|
27
|
Banik S, Das PK, Bendounan A, Vobornik I, Arya A, Beaulieu N, Fujii J, Thamizhavel A, Sastry PU, Sinha AK, Phase DM, Deb SK. Giant Rashba effect at the topological surface of PrGe revealing antiferromagnetic spintronics. Sci Rep 2017; 7:4120. [PMID: 28646153 PMCID: PMC5482886 DOI: 10.1038/s41598-017-02401-z] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/03/2016] [Accepted: 04/11/2017] [Indexed: 11/17/2022] Open
Abstract
Rashba spin-orbit splitting in the magnetic materials opens up a new perspective in the field of spintronics. Here, we report a giant Rashba spin-orbit splitting on the PrGe [010] surface in the paramagnetic phase with Rashba coefficient α R = 5 eVÅ. We find that α R can be tuned in this system as a function of temperature at different magnetic phases. Rashba type spin polarized surface states originates due to the strong hybridization between Pr 4f states with the conduction electrons. Significant changes observed in the spin polarized surface states across the magnetic transitions are due to the competition between Dzyaloshinsky-Moriya interaction and exchange interaction present in this system. Presence of Dzyaloshinsky-Moriya interaction on the topological surface give rise to Saddle point singularity which leads to electron-like and hole-like Rashba spin split bands in the [Formula: see text] and [Formula: see text] directions, respectively. Supporting evidences of Dzyaloshinsky-Moriya interaction have been obtained as anisotropic magnetoresistance with respect to field direction and first-order type hysteresis in the X-ray diffraction measurements. A giant negative magnetoresistance of 43% in the antiferromagnetic phase and tunable Rashba parameter with temperature makes this material a suitable candidate for application in the antiferromagnetic spintronic devices.
Collapse
Affiliation(s)
- Soma Banik
- Synchrotrons Utilization Section, Raja Ramanna Centre for Advanced Technology, Indore, 452013, India.
| | - Pranab Kumar Das
- Department of Condensed Matter Physics and Materials Science, Tata Institute of Fundamental Research, Homi Bhabha Road, Colaba, Mumbai, 400005, India
- International Centre for Theoretical Physics, Strada Costiera 11, 34100, Trieste, Italy
| | - Azzedine Bendounan
- Synchrotron SOLEIL, L'Orme des Merisiers, Saint-Aubin, BP 48, FR-91192, Gif-sur-Yvette Cedex, France
| | - Ivana Vobornik
- Istituto Officina dei Materiali (IOM)-CNR, Laboratorio TASC, in Area Science Park, S.S.14, Km 163.5, I-34149, Trieste, Italy
| | - A Arya
- Materials Science Division, Bhabha Atomic Research Centre, Mumbai, 400085, India
| | - Nathan Beaulieu
- Synchrotron SOLEIL, L'Orme des Merisiers, Saint-Aubin, BP 48, FR-91192, Gif-sur-Yvette Cedex, France
| | - Jun Fujii
- Istituto Officina dei Materiali (IOM)-CNR, Laboratorio TASC, in Area Science Park, S.S.14, Km 163.5, I-34149, Trieste, Italy
| | - A Thamizhavel
- Department of Condensed Matter Physics and Materials Science, Tata Institute of Fundamental Research, Homi Bhabha Road, Colaba, Mumbai, 400005, India
| | - P U Sastry
- Solid State Physics Division, Bhabha Atomic Research Centre, Mumbai, 400085, India
| | - A K Sinha
- Synchrotrons Utilization Section, Raja Ramanna Centre for Advanced Technology, Indore, 452013, India
| | - D M Phase
- UGC-DAE Consortium for Scientific Research, Khandwa Road, Indore, 452001, India
| | - S K Deb
- Synchrotrons Utilization Section, Raja Ramanna Centre for Advanced Technology, Indore, 452013, India
- Indian Institute of Technology Bombay, Powai, Mumbai, 400076, India
| |
Collapse
|
28
|
Hellman F, Hoffmann A, Tserkovnyak Y, Beach GSD, Fullerton EE, Leighton C, MacDonald AH, Ralph DC, Arena DA, Dürr HA, Fischer P, Grollier J, Heremans JP, Jungwirth T, Kimel AV, Koopmans B, Krivorotov IN, May SJ, Petford-Long AK, Rondinelli JM, Samarth N, Schuller IK, Slavin AN, Stiles MD, Tchernyshyov O, Thiaville A, Zink BL. Interface-Induced Phenomena in Magnetism. REVIEWS OF MODERN PHYSICS 2017; 89:025006. [PMID: 28890576 PMCID: PMC5587142 DOI: 10.1103/revmodphys.89.025006] [Citation(s) in RCA: 181] [Impact Index Per Article: 25.9] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/21/2023]
Abstract
This article reviews static and dynamic interfacial effects in magnetism, focusing on interfacially-driven magnetic effects and phenomena associated with spin-orbit coupling and intrinsic symmetry breaking at interfaces. It provides a historical background and literature survey, but focuses on recent progress, identifying the most exciting new scientific results and pointing to promising future research directions. It starts with an introduction and overview of how basic magnetic properties are affected by interfaces, then turns to a discussion of charge and spin transport through and near interfaces and how these can be used to control the properties of the magnetic layer. Important concepts include spin accumulation, spin currents, spin transfer torque, and spin pumping. An overview is provided to the current state of knowledge and existing review literature on interfacial effects such as exchange bias, exchange spring magnets, spin Hall effect, oxide heterostructures, and topological insulators. The article highlights recent discoveries of interface-induced magnetism and non-collinear spin textures, non-linear dynamics including spin torque transfer and magnetization reversal induced by interfaces, and interfacial effects in ultrafast magnetization processes.
Collapse
Affiliation(s)
- Frances Hellman
- Department of Physics, University of California, Berkeley, Berkeley, California 94720, USA; Materials Sciences Division, Lawrence Berkeley National Laboratory, Berkeley, California 94720, USA
| | - Axel Hoffmann
- Materials Science Division, Argonne National Laboratory, Argonne, Illinois 60439, USA
| | - Yaroslav Tserkovnyak
- Department of Physics and Astronomy, University of California, Los Angeles, California 90095, USA
| | - Geoffrey S D Beach
- Department of Materials Science and Engineering, Massachusetts Institute of Technology, Cambridge, Massachusetts 02139, USA
| | - Eric E Fullerton
- Center for Memory and Recording Research, University of California, San Diego, 9500 Gilman Drive, La Jolla, California 92093-0401, USA
| | - Chris Leighton
- Department of Chemical Engineering and Materials Science, University of Minnesota, Minneapolis, Minnesota 55455, USA
| | - Allan H MacDonald
- Department of Physics, University of Texas at Austin, Austin, Texas 78712-0264, USA
| | - Daniel C Ralph
- Physics Department, Cornell University, Ithaca, New York 14853, USA; Kavli Institute at Cornell, Cornell University, Ithaca, New York 14853, USA
| | - Dario A Arena
- Department of Physics, University of South Florida, Tampa, Florida 33620-7100, USA
| | - Hermann A Dürr
- Stanford Institute for Materials and Energy Sciences, SLAC National Accelerator Laboratory, 2575 Sand Hill Road, Menlo Park, California 94025, USA
| | - Peter Fischer
- Materials Sciences Division, Lawrence Berkeley National Laboratory, Berkeley, California 94720, USA; Physics Department, University of California, 1156 High Street, Santa Cruz, California 94056, USA
| | - Julie Grollier
- Unité Mixte de Physique CNRS/Thales and Université Paris Sud 11, 1 Avenue Fresnel, 91767 Palaiseau, France
| | - Joseph P Heremans
- Department of Mechanical and Aerospace Engineering, The Ohio State University, Columbus, Ohio 43210, USA; Department of Materials Science and Engineering, The Ohio State University, Columbus, Ohio 43210, USA; Department of Physics, The Ohio State University, Columbus, Ohio 43210, USA
| | - Tomas Jungwirth
- Institute of Physics, Academy of Sciences of the Czech Republic, Cukrovarnicka 10, 162 53 Praha 6, Czech Republic; School of Physics and Astronomy, University of Nottingham, Nottingham NG7 2RD, United Kingdom
| | - Alexey V Kimel
- Radboud University, Institute for Molecules and Materials, Nijmegen 6525 AJ, The Netherlands
| | - Bert Koopmans
- Department of Applied Physics, Center for NanoMaterials, COBRA Research Institute, Eindhoven University of Technology, P.O. Box 513, 5600 MB Eindhoven, The Netherlands
| | - Ilya N Krivorotov
- Department of Physics and Astronomy, University of California, Irvine, California 92697, USA
| | - Steven J May
- Department of Materials Science & Engineering, Drexel University, Philadelphia, Pennsylvania 19104, USA
| | - Amanda K Petford-Long
- Materials Science Division, Argonne National Laboratory, 9700 South Cass Avenue, Argonne, Illinois 60439, USA; Department of Materials Science and Engineering, Northwestern University, 2220 Campus Drive, Evanston, Illinois 60208, USA
| | - James M Rondinelli
- Department of Materials Science and Engineering, Northwestern University, Evanston, Illinois 60208, USA
| | - Nitin Samarth
- Department of Physics, The Pennsylvania State University, University Park, Pennsylvania 16802, USA
| | - Ivan K Schuller
- Department of Physics and Center for Advanced Nanoscience, University of California, San Diego, La Jolla, California 92093, USA; Materials Science and Engineering Program, University of California, San Diego, La Jolla, California 92093, USA
| | - Andrei N Slavin
- Department of Physics, Oakland University, Rochester, Michigan 48309, USA
| | - Mark D Stiles
- Center for Nanoscale Science and Technology, National Institute of Standards and Technology, Gaithersburg, Maryland 20899-6202, USA
| | - Oleg Tchernyshyov
- Department of Physics and Astronomy, The Johns Hopkins University, Baltimore, Maryland 21218, USA
| | - André Thiaville
- Laboratoire de Physique des Solides, UMR CNRS 8502, Université Paris-Sud, 91405 Orsay, France
| | - Barry L Zink
- Department of Physics and Astronomy, University of Denver, Denver, CO 80208, USA
| |
Collapse
|
29
|
Qaiumzadeh A, Skarsvåg H, Holmqvist C, Brataas A. Spin Superfluidity in Biaxial Antiferromagnetic Insulators. PHYSICAL REVIEW LETTERS 2017; 118:137201. [PMID: 28409991 DOI: 10.1103/physrevlett.118.137201] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 12/13/2016] [Indexed: 06/07/2023]
Abstract
Antiferromagnets may exhibit spin superfluidity since the dipole interaction is weak. We seek to establish that this phenomenon occurs in insulators such as NiO, which is a good spin conductor according to previous studies. We investigate nonlocal spin transport in a planar antiferromagnetic insulator with a weak uniaxial anisotropy. The anisotropy hinders spin superfluidity by creating a substantial threshold that the current must overcome. Nevertheless, we show that applying a high magnetic field removes this obstacle near the spin-flop transition of the antiferromagnet. Importantly, the spin superfluidity can then persist across many micrometers, even in dirty samples.
Collapse
Affiliation(s)
- Alireza Qaiumzadeh
- Department of Physics, Norwegian University of Science and Technology, NO-7491 Trondheim, Norway
| | - Hans Skarsvåg
- Department of Physics, Norwegian University of Science and Technology, NO-7491 Trondheim, Norway
| | - Cecilia Holmqvist
- Department of Physics, Norwegian University of Science and Technology, NO-7491 Trondheim, Norway
| | - Arne Brataas
- Department of Physics, Norwegian University of Science and Technology, NO-7491 Trondheim, Norway
| |
Collapse
|
30
|
Galceran R, Fina I, Cisneros-Fernández J, Bozzo B, Frontera C, López-Mir L, Deniz H, Park KW, Park BG, Balcells L, Martí X, Jungwirth T, Martínez B. Isothermal anisotropic magnetoresistance in antiferromagnetic metallic IrMn. Sci Rep 2016; 6:35471. [PMID: 27762278 PMCID: PMC5071853 DOI: 10.1038/srep35471] [Citation(s) in RCA: 19] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/23/2016] [Accepted: 09/28/2016] [Indexed: 11/09/2022] Open
Abstract
Antiferromagnetic spintronics is an emerging field; antiferromagnets can improve the functionalities of ferromagnets with higher response times, and having the information shielded against external magnetic field. Moreover, a large list of aniferromagnetic semiconductors and metals with Néel temperatures above room temperature exists. In the present manuscript, we persevere in the quest for the limits of how large can anisotropic magnetoresistance be in antiferromagnetic materials with very large spin-orbit coupling. We selected IrMn as a prime example of first-class moment (Mn) and spin-orbit (Ir) combination. Isothermal magnetotransport measurements in an antiferromagnetic-metal(IrMn)/ferromagnetic-insulator thin film bilayer have been performed. The metal/insulator structure with magnetic coupling between both layers allows the measurement of the modulation of the transport properties exclusively in the antiferromagnetic layer. Anisotropic magnetoresistance as large as 0.15% has been found, which is much larger than that for a bare IrMn layer. Interestingly, it has been observed that anisotropic magnetoresistance is strongly influenced by the field cooling conditions, signaling the dependence of the found response on the formation of domains at the magnetic ordering temperature.
Collapse
Affiliation(s)
- R Galceran
- Institut de Ciència de Materials de Barcelona (CSIC), Campus de Bellaterra, 08193 Bellaterra, Spain.,Unité Mixte de Physique, CNRS, Thales, Université Paris-Sud, Université Paris-Saclay, Palaiseau 91767, France
| | - I Fina
- Institut de Ciència de Materials de Barcelona (CSIC), Campus de Bellaterra, 08193 Bellaterra, Spain.,Catalan Institute of Nanoscience and Nanotechnology (ICN2), CSIC and The Barcelona Institute of Science and Technology, Campus UAB, Bellaterra, 08193 Barcelona, Spain
| | - J Cisneros-Fernández
- Institut de Ciència de Materials de Barcelona (CSIC), Campus de Bellaterra, 08193 Bellaterra, Spain
| | - B Bozzo
- Institut de Ciència de Materials de Barcelona (CSIC), Campus de Bellaterra, 08193 Bellaterra, Spain
| | - C Frontera
- Institut de Ciència de Materials de Barcelona (CSIC), Campus de Bellaterra, 08193 Bellaterra, Spain
| | - L López-Mir
- Institut de Ciència de Materials de Barcelona (CSIC), Campus de Bellaterra, 08193 Bellaterra, Spain
| | - H Deniz
- Max Planck Institute of Microstructure Physics, Weinberg 2, D-06120 Halle (Saale), Germany
| | - K-W Park
- Department of Materials Science and Engineering, KAIST, Daejeon 305-701, Republic of Korea
| | - B-G Park
- Department of Materials Science and Engineering, KAIST, Daejeon 305-701, Republic of Korea
| | - Ll Balcells
- Institut de Ciència de Materials de Barcelona (CSIC), Campus de Bellaterra, 08193 Bellaterra, Spain
| | - X Martí
- Institute of Physics, Academy of Sciences of the Czech Republic, v.v.i., CZ-16253 Praha 6, Czech Republic
| | - T Jungwirth
- Institute of Physics, Academy of Sciences of the Czech Republic, v.v.i., CZ-16253 Praha 6, Czech Republic.,School of Physics and Astronomy, University of Nottingham, Nottingham NG7 2RD, United Kingdom
| | - B Martínez
- Institut de Ciència de Materials de Barcelona (CSIC), Campus de Bellaterra, 08193 Bellaterra, Spain
| |
Collapse
|
31
|
Gilbert DA, Olamit J, Dumas RK, Kirby BJ, Grutter AJ, Maranville BB, Arenholz E, Borchers JA, Liu K. Controllable positive exchange bias via redox-driven oxygen migration. Nat Commun 2016; 7:11050. [PMID: 26996674 PMCID: PMC4802176 DOI: 10.1038/ncomms11050] [Citation(s) in RCA: 85] [Impact Index Per Article: 10.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/30/2015] [Accepted: 02/16/2016] [Indexed: 12/01/2022] Open
Abstract
Ionic transport in metal/oxide heterostructures offers a highly effective means to tailor material properties via modification of the interfacial characteristics. However, direct observation of ionic motion under buried interfaces and demonstration of its correlation with physical properties has been challenging. Using the strong oxygen affinity of gadolinium, we design a model system of GdxFe1-x/NiCoO bilayer films, where the oxygen migration is observed and manifested in a controlled positive exchange bias over a relatively small cooling field range. The exchange bias characteristics are shown to be the result of an interfacial layer of elemental nickel and cobalt, a few nanometres in thickness, whose moments are larger than expected from uncompensated NiCoO moments. This interface layer is attributed to a redox-driven oxygen migration from NiCoO to the gadolinium, during growth or soon after. These results demonstrate an effective path to tailoring the interfacial characteristics and interlayer exchange coupling in metal/oxide heterostructures.
Collapse
Affiliation(s)
- Dustin A. Gilbert
- Physics Department, University of California, Davis, One Shields Avenue, Davis, California 95616, USA
- NIST Center for Neutron Research, Gaithersburg, Maryland 20899, USA
| | - Justin Olamit
- Physics Department, University of California, Davis, One Shields Avenue, Davis, California 95616, USA
| | - Randy K. Dumas
- Physics Department, University of California, Davis, One Shields Avenue, Davis, California 95616, USA
- Department of Physics, University of Gothenburg, Gothenburg 412 96, Sweden
| | - B. J. Kirby
- NIST Center for Neutron Research, Gaithersburg, Maryland 20899, USA
| | | | | | - Elke Arenholz
- Advanced Light Source, Lawrence Berkeley National Laboratory, Berkeley, California 94720, USA
| | | | - Kai Liu
- Physics Department, University of California, Davis, One Shields Avenue, Davis, California 95616, USA
| |
Collapse
|
32
|
Jungwirth T, Marti X, Wadley P, Wunderlich J. Antiferromagnetic spintronics. NATURE NANOTECHNOLOGY 2016; 11:231-41. [PMID: 26936817 DOI: 10.1038/nnano.2016.18] [Citation(s) in RCA: 432] [Impact Index Per Article: 54.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 08/26/2015] [Accepted: 01/25/2016] [Indexed: 05/22/2023]
Abstract
Antiferromagnetic materials are internally magnetic, but the direction of their ordered microscopic moments alternates between individual atomic sites. The resulting zero net magnetic moment makes magnetism in antiferromagnets externally invisible. This implies that information stored in antiferromagnetic moments would be invisible to common magnetic probes, insensitive to disturbing magnetic fields, and the antiferromagnetic element would not magnetically affect its neighbours, regardless of how densely the elements are arranged in the device. The intrinsic high frequencies of antiferromagnetic dynamics represent another property that makes antiferromagnets distinct from ferromagnets. Among the outstanding questions is how to manipulate and detect the magnetic state of an antiferromagnet efficiently. In this Review we focus on recent works that have addressed this question. The field of antiferromagnetic spintronics can also be viewed from the general perspectives of spin transport, magnetic textures and dynamics, and materials research. We briefly mention this broader context, together with an outlook of future research and applications of antiferromagnetic spintronics.
Collapse
Affiliation(s)
- T Jungwirth
- Institute of Physics, Academy of Sciences of the Czech Republic, Cukrovarnická 10, 162 53 Praha 6, Czech Republic
- School of Physics and Astronomy, University of Nottingham, Nottingham NG7 2RD, UK
| | - X Marti
- Institute of Physics, Academy of Sciences of the Czech Republic, Cukrovarnická 10, 162 53 Praha 6, Czech Republic
| | - P Wadley
- School of Physics and Astronomy, University of Nottingham, Nottingham NG7 2RD, UK
| | - J Wunderlich
- Institute of Physics, Academy of Sciences of the Czech Republic, Cukrovarnická 10, 162 53 Praha 6, Czech Republic
- Hitachi Cambridge Laboratory, Cambridge CB3 0HE, UK
| |
Collapse
|
33
|
Wadley P, Howells B, Železný J, Andrews C, Hills V, Campion RP, Novák V, Olejník K, Maccherozzi F, Dhesi SS, Martin SY, Wagner T, Wunderlich J, Freimuth F, Mokrousov Y, Kuneš J, Chauhan JS, Grzybowski MJ, Rushforth AW, Edmonds KW, Gallagher BL, Jungwirth T. Electrical switching of an antiferromagnet. Science 2016; 351:587-90. [PMID: 26841431 DOI: 10.1126/science.aab1031] [Citation(s) in RCA: 297] [Impact Index Per Article: 37.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/11/2015] [Accepted: 01/04/2016] [Indexed: 11/02/2022]
Abstract
Antiferromagnets are hard to control by external magnetic fields because of the alternating directions of magnetic moments on individual atoms and the resulting zero net magnetization. However, relativistic quantum mechanics allows for generating current-induced internal fields whose sign alternates with the periodicity of the antiferromagnetic lattice. Using these fields, which couple strongly to the antiferromagnetic order, we demonstrate room-temperature electrical switching between stable configurations in antiferromagnetic CuMnAs thin-film devices by applied current with magnitudes of order 10(6) ampere per square centimeter. Electrical writing is combined in our solid-state memory with electrical readout and the stored magnetic state is insensitive to and produces no external magnetic field perturbations, which illustrates the unique merits of antiferromagnets for spintronics.
Collapse
Affiliation(s)
- P Wadley
- School of Physics and Astronomy, University of Nottingham, Nottingham NG7 2RD, UK.
| | - B Howells
- School of Physics and Astronomy, University of Nottingham, Nottingham NG7 2RD, UK
| | - J Železný
- Institute of Physics, Academy of Sciences of the Czech Republic, Cukrovarnická 10, 162 00 Praha 6, Czech Republic. Faculty of Mathematics and Physics, Charles University, Ke Karlovu 3, 121 16 Prague 2, Czech Republic
| | - C Andrews
- School of Physics and Astronomy, University of Nottingham, Nottingham NG7 2RD, UK
| | - V Hills
- School of Physics and Astronomy, University of Nottingham, Nottingham NG7 2RD, UK
| | - R P Campion
- School of Physics and Astronomy, University of Nottingham, Nottingham NG7 2RD, UK
| | - V Novák
- Institute of Physics, Academy of Sciences of the Czech Republic, Cukrovarnická 10, 162 00 Praha 6, Czech Republic
| | - K Olejník
- Institute of Physics, Academy of Sciences of the Czech Republic, Cukrovarnická 10, 162 00 Praha 6, Czech Republic
| | - F Maccherozzi
- Diamond Light Source, Chilton, Didcot, Oxfordshire, OX11 0DE, UK
| | - S S Dhesi
- Diamond Light Source, Chilton, Didcot, Oxfordshire, OX11 0DE, UK
| | - S Y Martin
- Hitachi Cambridge Laboratory, J. J. Thomson Avenue, Cambridge CB3 0HE, UK
| | - T Wagner
- Hitachi Cambridge Laboratory, J. J. Thomson Avenue, Cambridge CB3 0HE, UK. Department of Materials Science and Metallurgy, University of Cambridge, Cambridge CB3 0HE, UK
| | - J Wunderlich
- Institute of Physics, Academy of Sciences of the Czech Republic, Cukrovarnická 10, 162 00 Praha 6, Czech Republic. Hitachi Cambridge Laboratory, J. J. Thomson Avenue, Cambridge CB3 0HE, UK
| | - F Freimuth
- Peter Grünberg Institut and Institute for Advanced Simulation, Forschungszentrum Jülich and JARA, 52425 Jülich, Germany
| | - Y Mokrousov
- Peter Grünberg Institut and Institute for Advanced Simulation, Forschungszentrum Jülich and JARA, 52425 Jülich, Germany
| | - J Kuneš
- Institute of Physics, Academy of Sciences of the Czech Republic, Na Slovance 2, 182 21 Praha 8, Czech Republic
| | - J S Chauhan
- School of Physics and Astronomy, University of Nottingham, Nottingham NG7 2RD, UK
| | - M J Grzybowski
- School of Physics and Astronomy, University of Nottingham, Nottingham NG7 2RD, UK. Institute of Physics, Polish Academy of Sciences, al. Lotnikow 32/46, PL-02-668 Warsaw, Poland
| | - A W Rushforth
- School of Physics and Astronomy, University of Nottingham, Nottingham NG7 2RD, UK
| | - K W Edmonds
- School of Physics and Astronomy, University of Nottingham, Nottingham NG7 2RD, UK
| | - B L Gallagher
- School of Physics and Astronomy, University of Nottingham, Nottingham NG7 2RD, UK
| | - T Jungwirth
- Institute of Physics, Academy of Sciences of the Czech Republic, Cukrovarnická 10, 162 00 Praha 6, Czech Republic. School of Physics and Astronomy, University of Nottingham, Nottingham NG7 2RD, UK
| |
Collapse
|
34
|
Wang K, Sanderink JGM, Bolhuis T, van der Wiel WG, de Jong MP. Tunnelling anisotropic magnetoresistance due to antiferromagnetic CoO tunnel barriers. Sci Rep 2015; 5:15498. [PMID: 26486931 PMCID: PMC4614445 DOI: 10.1038/srep15498] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/30/2015] [Accepted: 09/28/2015] [Indexed: 11/12/2022] Open
Abstract
A new approach in spintronics is based on spin-polarized charge transport phenomena governed by antiferromagnetic (AFM) materials. Recent studies have demonstrated the feasibility of this approach for AFM metals and semiconductors. We report tunneling anisotropic magnetoresistance (TAMR) due to the rotation of antiferromagnetic moments of an insulating CoO layer, incorporated into a tunnel junction consisting of sapphire(substrate)/fcc-Co/CoO/AlOx/Al. The ferromagnetic Co layer is exchange coupled to the AFM CoO layer and drives rotation of the AFM moments in an external magnetic field. The results may help pave the way towards the development of spintronic devices based on AFM insulators.
Collapse
Affiliation(s)
- K. Wang
- NanoElectronics Group, MESA+ Institute for Nanotechnology, University of Twente, P.O. Box 217, Enschede, 7500AE, The Netherlands
| | - J. G. M. Sanderink
- NanoElectronics Group, MESA+ Institute for Nanotechnology, University of Twente, P.O. Box 217, Enschede, 7500AE, The Netherlands
| | - T. Bolhuis
- NanoElectronics Group, MESA+ Institute for Nanotechnology, University of Twente, P.O. Box 217, Enschede, 7500AE, The Netherlands
| | - W. G. van der Wiel
- NanoElectronics Group, MESA+ Institute for Nanotechnology, University of Twente, P.O. Box 217, Enschede, 7500AE, The Netherlands
| | - M. P. de Jong
- NanoElectronics Group, MESA+ Institute for Nanotechnology, University of Twente, P.O. Box 217, Enschede, 7500AE, The Netherlands
| |
Collapse
|
35
|
Gilbert DA, Ye L, Varea A, Agramunt-Puig S, del Valle N, Navau C, López-Barbera JF, Buchanan KS, Hoffmann A, Sánchez A, Sort J, Liu K, Nogués J. A new reversal mode in exchange coupled antiferromagnetic/ferromagnetic disks: distorted viscous vortex. NANOSCALE 2015; 7:9878-9885. [PMID: 25965577 DOI: 10.1039/c5nr01856k] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/04/2023]
Abstract
Magnetic vortices have generated intense interest in recent years due to their unique reversal mechanisms, fascinating topological properties, and exciting potential applications. In addition, the exchange coupling of magnetic vortices to antiferromagnets has also been shown to lead to a range of novel phenomena and functionalities. Here we report a new magnetization reversal mode of magnetic vortices in exchange coupled Ir20Mn80/Fe20Ni80 microdots: distorted viscous vortex reversal. In contrast to the previously known or proposed reversal modes, the vortex is distorted close to the interface and viscously dragged due to the uncompensated spins of a thin antiferromagnet, which leads to unexpected asymmetries in the annihilation and nucleation fields. These results provide a deeper understanding of the physics of exchange coupled vortices and may also have important implications for applications involving exchange coupled nanostructures.
Collapse
|
36
|
Domingo N, López-Mir L, Paradinas M, Holy V, Železný J, Yi D, Suresha SJ, Liu J, Rayan Serrao C, Ramesh R, Ocal C, Martí X, Catalan G. Giant reversible nanoscale piezoresistance at room temperature in Sr2IrO4 thin films. NANOSCALE 2015; 7:3453-3459. [PMID: 25649123 DOI: 10.1039/c4nr06954d] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/04/2023]
Abstract
Layered iridates have been the subject of intense scrutiny on account of their unusually strong spin-orbit coupling, which opens up a narrow bandgap in a material that would otherwise be a metal. This insulating state is very sensitive to external perturbations. Here, we show that vertical compression at the nanoscale, delivered using the tip of a standard scanning probe microscope, is capable of inducing a five orders of magnitude change in the room temperature resistivity of Sr2IrO4. The extreme sensitivity of the electronic structure to anisotropic deformations opens up a new angle of interest on this material, with the giant and fully reversible perpendicular piezoresistance rendering iridates as promising materials for room temperature piezotronic devices.
Collapse
Affiliation(s)
- Neus Domingo
- ICN2-Institut Català de Nanociència i Nanotecnologia, Campus Universitat Autònoma de Barcelona, 08193 Bellaterra, Spain.
| | | | | | | | | | | | | | | | | | | | | | | | | |
Collapse
|
37
|
Železný J, Gao H, Výborný K, Zemen J, Mašek J, Manchon A, Wunderlich J, Sinova J, Jungwirth T. Relativistic Néel-order fields induced by electrical current in antiferromagnets. PHYSICAL REVIEW LETTERS 2014; 113:157201. [PMID: 25375735 DOI: 10.1103/physrevlett.113.157201] [Citation(s) in RCA: 97] [Impact Index Per Article: 9.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 06/02/2014] [Indexed: 06/04/2023]
Abstract
We predict that a lateral electrical current in antiferromagnets can induce nonequilibrium Néel-order fields, i.e., fields whose sign alternates between the spin sublattices, which can trigger ultrafast spin-axis reorientation. Based on microscopic transport theory calculations we identify staggered current-induced fields analogous to the intraband and to the intrinsic interband spin-orbit fields previously reported in ferromagnets with a broken inversion-symmetry crystal. To illustrate their rich physics and utility, we consider bulk Mn(2)Au with the two spin sublattices forming inversion partners, and a 2D square-lattice antiferromagnet with broken structural inversion symmetry modeled by a Rashba spin-orbit coupling. We propose an antiferromagnetic memory device with electrical writing and reading.
Collapse
Affiliation(s)
- J Železný
- Institute of Physics ASCR, Cukrovarnická 10, 162 53 Praha 6, Czech Republic and Faculty of Mathematics and Physics, Charles University in Prague, Ke Karlovu 3, 121 16 Prague 2, Czech Republic
| | - H Gao
- Department of Physics, Texas A&M University, College Station, Texas 77843-4242, USA
| | - K Výborný
- Institute of Physics ASCR, Cukrovarnická 10, 162 53 Praha 6, Czech Republic
| | - J Zemen
- Department of Physics, Blackett Laboratory, Imperial College London, London SW7 2AZ, United Kingdom
| | - J Mašek
- Institute of Physics ASCR, Na Slovance 2, 182 21 Praha 8, Czech Republic
| | - Aurélien Manchon
- Physical Science and Engineering Division, King Abdullah University of Science and Technology (KAUST), Thuwal 23955-6900, Kingdom of Saudi Arabia
| | - J Wunderlich
- Institute of Physics ASCR, Cukrovarnická 10, 162 53 Praha 6, Czech Republic and Hitachi Cambridge Laboratory, Cambridge CB3 0HE, United Kingdom
| | - Jairo Sinova
- Institute of Physics ASCR, Cukrovarnická 10, 162 53 Praha 6, Czech Republic and Department of Physics, Texas A&M University, College Station, Texas 77843-4242, USA and Institut für Physik, Johannes Gutenberg Universität Mainz, 55128 Mainz, Germany
| | - T Jungwirth
- Institute of Physics ASCR, Cukrovarnická 10, 162 53 Praha 6, Czech Republic and School of Physics and Astronomy, University of Nottingham, Nottingham NG7 2RD, United Kingdom
| |
Collapse
|