151
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Ghosh P, Guo J, Ye F, Heitmann T, Kelley S, Ernst A, Dugaev V, Singh DK. NiSi: New Venue for Antiferromagnetic Spintronics. Adv Mater 2023:e2302120. [PMID: 37080560 DOI: 10.1002/adma.202302120] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/06/2023] [Revised: 04/02/2023] [Indexed: 05/03/2023]
Abstract
Envisaging antiferromagnetic spintronics pivots on two key criteria of high transition temperature and tuning of underlying magnetic order using straightforward application of magnetic field or electric current. Here, we show that NiSi metal can provide suitable new platform in this quest. First, our study unveils high temperature antiferromagnetism in single crystal NiSi with TN ⩾ 700 K. Antiferromagnetic order in NiSi is accompanied by the non-centrosymmetric magnetic character with small ferromagnetic component in a-c plane. Second, we find that NiSi manifests distinct magnetic and electronic hysteresis responses to field applications due to the disparity in two moment directions. While magnetic hysteresis is characterized by one-step switching between ferromagnetic states of uncompensated moment, electronic behavior is ascribed to metamagnetic switching phenomena between non-collinear spin configurations. Importantly, the switching behaviors persist to high temperature. The properties underscore the importance of NiSi in the pursuit of antiferromagnetic spintronics. This article is protected by copyright. All rights reserved.
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Affiliation(s)
- P Ghosh
- Department of Physics and Astronomy, University of Missouri, Columbia, MO, USA
| | - J Guo
- Department of Physics and Astronomy, University of Missouri, Columbia, MO, USA
| | - F Ye
- Oak Ridge National Laboratory, Oak Ridge, TN, USA
| | - T Heitmann
- University of Missouri Research Reactor, Columbia, MO, USA
| | - S Kelley
- Department of Chemistry, University of Missouri, Columbia, MO, USA
| | - A Ernst
- Institut for Theoretical Physics, Johannes Kepler University, Linz, Austria
| | - V Dugaev
- Department of Physics and Medical Engineering, Rzeszów University of Technology, Rzeszów, Poland
| | - D K Singh
- Department of Physics and Astronomy, University of Missouri, Columbia, MO, USA
- MU Materials Science and Engineering Institute, Columbia, MO, USA
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152
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Attanayake SB, Chanda A, Hulse T, Das R, Phan MH, Srikanth H. Competing Magnetic Interactions and Field-Induced Metamagnetic Transition in Highly Crystalline Phase-Tunable Iron Oxide Nanorods. Nanomaterials (Basel) 2023; 13:1340. [PMID: 37110925 PMCID: PMC10145142 DOI: 10.3390/nano13081340] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 03/20/2023] [Revised: 04/07/2023] [Accepted: 04/10/2023] [Indexed: 06/19/2023]
Abstract
The inherent existence of multi phases in iron oxide nanostructures highlights the significance of them being investigated deliberately to understand and possibly control the phases. Here, the effects of annealing at 250 °C with a variable duration on the bulk magnetic and structural properties of high aspect ratio biphase iron oxide nanorods with ferrimagnetic Fe3O4 and antiferromagnetic α-Fe2O3 are explored. Increasing annealing time under a free flow of oxygen enhanced the α-Fe2O3 volume fraction and improved the crystallinity of the Fe3O4 phase, identified in changes in the magnetization as a function of annealing time. A critical annealing time of approximately 3 h maximized the presence of both phases, as observed via an enhancement in the magnetization and an interfacial pinning effect. This is attributed to disordered spins separating the magnetically distinct phases which tend to align with the application of a magnetic field at high temperatures. The increased antiferromagnetic phase can be distinguished due to the field-induced metamagnetic transitions observed in structures annealed for more than 3 h and was especially prominent in the 9 h annealed sample. Our controlled study in determining the changes in volume fractions with annealing time will enable precise control over phase tunability in iron oxide nanorods, allowing custom-made phase volume fractions in different applications ranging from spintronics to biomedical applications.
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Affiliation(s)
- Supun B. Attanayake
- Department of Physics, University of South Florida, Tampa, FL 33620, USA; (S.B.A.); (H.S.)
| | - Amit Chanda
- Department of Physics, University of South Florida, Tampa, FL 33620, USA; (S.B.A.); (H.S.)
| | - Thomas Hulse
- Department of Physics & Astronomy, University of Louisville, Louisville, KY 40208, USA;
| | - Raja Das
- SEAM Research Centre, South East Technological University, X91 K0EK Waterford, Ireland;
| | - Manh-Huong Phan
- Department of Physics, University of South Florida, Tampa, FL 33620, USA; (S.B.A.); (H.S.)
| | - Hariharan Srikanth
- Department of Physics, University of South Florida, Tampa, FL 33620, USA; (S.B.A.); (H.S.)
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153
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Jensen CJ, Quintana A, Quarterman P, Grutter AJ, Balakrishnan PP, Zhang H, Davydov AV, Zhang X, Liu K. Nitrogen-Based Magneto-ionic Manipulation of Exchange Bias in CoFe/MnN Heterostructures. ACS Nano 2023; 17:6745-6753. [PMID: 36995303 PMCID: PMC10950296 DOI: 10.1021/acsnano.2c12702] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/19/2023]
Abstract
Electric field control of the exchange bias effect across ferromagnet/antiferromagnet (FM/AF) interfaces has offered exciting potentials for low-energy-dissipation spintronics. In particular, the solid-state magneto-ionic means is highly appealing as it may allow reconfigurable electronics by transforming the all-important FM/AF interfaces through ionic migration. In this work, we demonstrate an approach that combines the chemically induced magneto-ionic effect with the electric field driving of nitrogen in the Ta/Co0.7Fe0.3/MnN/Ta structure to electrically manipulate exchange bias. Upon field-cooling the heterostructure, ionic diffusion of nitrogen from MnN into the Ta layers occurs. A significant exchange bias of 618 Oe at 300 K and 1484 Oe at 10 K is observed, which can be further enhanced after a voltage conditioning by 5 and 19%, respectively. This enhancement can be reversed by voltage conditioning with an opposite polarity. Nitrogen migration within the MnN layer and into the Ta capping layer cause the enhancement in exchange bias, which is observed in polarized neutron reflectometry studies. These results demonstrate an effective nitrogen-ion based magneto-ionic manipulation of exchange bias in solid-state devices.
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Affiliation(s)
- Christopher J Jensen
- Physics Department, Georgetown University, Washington, D.C. 20057, United States
| | - Alberto Quintana
- Physics Department, Georgetown University, Washington, D.C. 20057, United States
| | - Patrick Quarterman
- NIST Center for Neutron Research, NCNR, National Institute of Standards and Technology, Gaithersburg, Maryland 20899, United States
| | - Alexander J Grutter
- NIST Center for Neutron Research, NCNR, National Institute of Standards and Technology, Gaithersburg, Maryland 20899, United States
| | - Purnima P Balakrishnan
- NIST Center for Neutron Research, NCNR, National Institute of Standards and Technology, Gaithersburg, Maryland 20899, United States
| | - Huairuo Zhang
- Theiss Research, Inc., La Jolla, California 92037, United States
- NIST Materials Measurement Laboratory, National Institute of Standards and Technology, Gaithersburg, Maryland 20899, United States
| | - Albert V Davydov
- NIST Materials Measurement Laboratory, National Institute of Standards and Technology, Gaithersburg, Maryland 20899, United States
| | - Xixiang Zhang
- King Abdullah University of Science & Technology, Thuwal 23955-6900, Saudi Arabia
| | - Kai Liu
- Physics Department, Georgetown University, Washington, D.C. 20057, United States
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154
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Gruber R, Brems MA, Rothörl J, Sparmann T, Schmitt M, Kononenko I, Kammerbauer F, Syskaki MA, Farago O, Virnau P, Kläui M. 300-Times-Increased Diffusive Skyrmion Dynamics and Effective Pinning Reduction by Periodic Field Excitation. Adv Mater 2023; 35:e2208922. [PMID: 36739114 DOI: 10.1002/adma.202208922] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 09/27/2022] [Revised: 01/30/2023] [Indexed: 05/17/2023]
Abstract
Thermally induced skyrmion dynamics, as well as skyrmion pinning effects, in thin films have attracted significant interest. While pinning poses challenges in deterministic skyrmion devices and slows down skyrmion diffusion, for applications in non-conventional computing, both pinning of an appropriate strength and skyrmion diffusion speed are key. Here, periodic field excitations are employed to realize an increase of the skyrmion diffusion by more than two orders of magnitude. Amplifying the excitation, a drastic reduction of the effective skyrmion pinning, is reported, and a transition from pinning-dominated diffusive hopping to dynamics approaching free diffusion is observed. By tailoring the field oscillation frequency and amplitude, a continuous tuning of the effective pinning and skyrmion dynamics is demonstrated, which is a key asset and enabler for non-conventional computing applications. It is found that the periodic excitations additionally allow stabilization of skyrmions at different sizes for field values that are inaccessible in static systems, opening up new approaches to ultrafast skyrmion motion by transiently exciting moving skyrmions.
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Affiliation(s)
- Raphael Gruber
- Johannes Gutenberg-Universität Mainz, Institut für Physik, Staudingerweg 7, 55128, Mainz, Germany
| | - Maarten A Brems
- Johannes Gutenberg-Universität Mainz, Institut für Physik, Staudingerweg 7, 55128, Mainz, Germany
| | - Jan Rothörl
- Johannes Gutenberg-Universität Mainz, Institut für Physik, Staudingerweg 7, 55128, Mainz, Germany
| | - Tobias Sparmann
- Johannes Gutenberg-Universität Mainz, Institut für Physik, Staudingerweg 7, 55128, Mainz, Germany
| | - Maurice Schmitt
- Johannes Gutenberg-Universität Mainz, Institut für Physik, Staudingerweg 7, 55128, Mainz, Germany
| | - Iryna Kononenko
- Johannes Gutenberg-Universität Mainz, Institut für Physik, Staudingerweg 7, 55128, Mainz, Germany
- National Academy of Sciences of Ukraine, Institute of Applied Physics, 58 Petropavlivska St., Sumy, 40000, Ukraine
| | - Fabian Kammerbauer
- Johannes Gutenberg-Universität Mainz, Institut für Physik, Staudingerweg 7, 55128, Mainz, Germany
| | - Maria-Andromachi Syskaki
- Johannes Gutenberg-Universität Mainz, Institut für Physik, Staudingerweg 7, 55128, Mainz, Germany
- Singulus Technologies AG, Hanauer Landstraße 103, 63796, Kahl am Main, Germany
| | - Oded Farago
- Biomedical Engineering Department, Ben Gurion University of the Negev, Be'er Sheva, 84105, Israel
| | - Peter Virnau
- Johannes Gutenberg-Universität Mainz, Institut für Physik, Staudingerweg 7, 55128, Mainz, Germany
| | - Mathias Kläui
- Johannes Gutenberg-Universität Mainz, Institut für Physik, Staudingerweg 7, 55128, Mainz, Germany
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155
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An T, Cui B, Liu L, Zhang M, Liu F, Liu W, Xie J, Ren X, Chu R, Cheng B, Jiang C, Hu J. Enhanced Spin Current in Ni 81 Fe 19 /Cu-CuO x Bilayer with Top and Sideways Oxidization. Adv Mater 2023; 35:e2207988. [PMID: 36630709 DOI: 10.1002/adma.202207988] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 09/01/2022] [Revised: 01/06/2023] [Indexed: 06/17/2023]
Abstract
Generation and manipulation of spin current are the cores of spintronic devices, which are intensely pursued. Heavy metals with strong spin-orbit coupling are commonly used for the generation of spin current, but are incompatible with the mass production of devices, and the polarization of spin current is limited to be in-plane. Here, it is shown that the spin current with strong out-of-plane polarization component can be generated and transmitted in Ni81 Fe19 /Cu-CuOx bilayer with sideways and top oxidizations. The charge-to-spin current conversion efficiency can be enhanced through the spin currents consisting of both out-of-plane polarization (σz ) and in-plane polarization (σy ) induced by spin-vorticity coupling. Such a spin current is demonstrated to be closely related to the lateral oxidization gradient and can be controlled by changing the temperatures and times of annealing. The finding here provides a novel degree of freedom to produce and control the spin current in spintronic devices.
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Affiliation(s)
- Taiyu An
- School of Physics, State Key Laboratory for Crystal Materials, Shandong University, Jinan, 250100, China
| | - Bin Cui
- School of Physics, State Key Laboratory for Crystal Materials, Shandong University, Jinan, 250100, China
| | - Liang Liu
- School of Physics, State Key Laboratory for Crystal Materials, Shandong University, Jinan, 250100, China
| | - Mingfang Zhang
- School of Physics, State Key Laboratory for Crystal Materials, Shandong University, Jinan, 250100, China
| | - Fufu Liu
- Key Laboratory for Magnetism and Magnetic Materials, Ministry of Education, Lanzhou University, Lanzhou, 730000, China
- Key Laboratory of Special Function Materials and Structure Design, Ministry of Education, Lanzhou University, Lanzhou, 730000, China
| | - Weikang Liu
- School of Physics, State Key Laboratory for Crystal Materials, Shandong University, Jinan, 250100, China
| | - Jihao Xie
- School of Physics, State Key Laboratory for Crystal Materials, Shandong University, Jinan, 250100, China
| | - Xue Ren
- School of Physics, State Key Laboratory for Crystal Materials, Shandong University, Jinan, 250100, China
| | - Ruiyue Chu
- School of Physics, State Key Laboratory for Crystal Materials, Shandong University, Jinan, 250100, China
| | - Bin Cheng
- School of Physics, State Key Laboratory for Crystal Materials, Shandong University, Jinan, 250100, China
| | - Changjun Jiang
- Key Laboratory for Magnetism and Magnetic Materials, Ministry of Education, Lanzhou University, Lanzhou, 730000, China
- Key Laboratory of Special Function Materials and Structure Design, Ministry of Education, Lanzhou University, Lanzhou, 730000, China
| | - Jifan Hu
- School of Physics, State Key Laboratory for Crystal Materials, Shandong University, Jinan, 250100, China
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156
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Lee J, Kwon J, Lee E, Park J, Cha S, Watanabe K, Taniguchi T, Jo MH, Choi H. Spinful hinge states in the higher-order topological insulators WTe 2. Nat Commun 2023; 14:1801. [PMID: 37002230 PMCID: PMC10066182 DOI: 10.1038/s41467-023-37482-0] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/05/2022] [Accepted: 03/20/2023] [Indexed: 04/03/2023] Open
Abstract
Higher-order topological insulators are recently discovered quantum materials exhibiting distinct topological phases with the generalized bulk-boundary correspondence. Td-WTe2 is a promising candidate to reveal topological hinge excitation in an atomically thin regime. However, with initial theories and experiments focusing on localized one-dimensional conductance only, no experimental reports exist on how the spin orientations are distributed over the helical hinges-this is critical, yet one missing puzzle. Here, we employ the magneto-optic Kerr effect to visualize the spinful characteristics of the hinge states in a few-layer Td-WTe2. By examining the spin polarization of electrons injected from WTe2 to graphene under external electric and magnetic fields, we conclude that WTe2 hosts a spinful and helical topological hinge state protected by the time-reversal symmetry. Our experiment provides a fertile diagnosis to investigate the topologically protected gapless hinge states, and may call for new theoretical studies to extend the previous spinless model.
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Affiliation(s)
- Jekwan Lee
- Department of Physics and Astronomy, Seoul National University, Seoul, 08826, Korea
- Institute of Applied Physics, Seoul National University, Seoul, 08826, Korea
| | - Jaehyeon Kwon
- Department of Physics and Astronomy, Seoul National University, Seoul, 08826, Korea
- Institute of Applied Physics, Seoul National University, Seoul, 08826, Korea
| | - Eunho Lee
- Department of Physics and Astronomy, Seoul National University, Seoul, 08826, Korea
- Institute of Applied Physics, Seoul National University, Seoul, 08826, Korea
| | - Jiwon Park
- Department of Physics and Astronomy, Seoul National University, Seoul, 08826, Korea
- Institute of Applied Physics, Seoul National University, Seoul, 08826, Korea
| | - Soonyoung Cha
- Center for Epitaxial van der Waals Quantum Solids, Institute for Basic Science, Pohang, 37673, Korea
- Department of Materials Science and Engineering, Pohang University of Science and Technoloagy, Pohang, 37673, Korea
| | - Kenji Watanabe
- Advanced Materials Laboratory, National Institute for Materials Science, 1-1 Namiki, Tsukuba, 305-0044, Japan
| | - Takashi Taniguchi
- Advanced Materials Laboratory, National Institute for Materials Science, 1-1 Namiki, Tsukuba, 305-0044, Japan
| | - Moon-Ho Jo
- Center for Epitaxial van der Waals Quantum Solids, Institute for Basic Science, Pohang, 37673, Korea
- Department of Materials Science and Engineering, Pohang University of Science and Technoloagy, Pohang, 37673, Korea
| | - Hyunyong Choi
- Department of Physics and Astronomy, Seoul National University, Seoul, 08826, Korea.
- Institute of Applied Physics, Seoul National University, Seoul, 08826, Korea.
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157
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Rongione E, Gueckstock O, Mattern M, Gomonay O, Meer H, Schmitt C, Ramos R, Kikkawa T, Mičica M, Saitoh E, Sinova J, Jaffrès H, Mangeney J, Goennenwein STB, Geprägs S, Kampfrath T, Kläui M, Bargheer M, Seifert TS, Dhillon S, Lebrun R. Emission of coherent THz magnons in an antiferromagnetic insulator triggered by ultrafast spin-phonon interactions. Nat Commun 2023; 14:1818. [PMID: 37002246 PMCID: PMC10066367 DOI: 10.1038/s41467-023-37509-6] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/07/2022] [Accepted: 03/20/2023] [Indexed: 04/03/2023] Open
Abstract
Antiferromagnetic materials have been proposed as new types of narrowband THz spintronic devices owing to their ultrafast spin dynamics. Manipulating coherently their spin dynamics, however, remains a key challenge that is envisioned to be accomplished by spin-orbit torques or direct optical excitations. Here, we demonstrate the combined generation of broadband THz (incoherent) magnons and narrowband (coherent) magnons at 1 THz in low damping thin films of NiO/Pt. We evidence, experimentally and through modeling, two excitation processes of spin dynamics in NiO: an off-resonant instantaneous optical spin torque in (111) oriented films and a strain-wave-induced THz torque induced by ultrafast Pt excitation in (001) oriented films. Both phenomena lead to the emission of a THz signal through the inverse spin Hall effect in the adjacent heavy metal layer. We unravel the characteristic timescales of the two excitation processes found to be < 50 fs and > 300 fs, respectively, and thus open new routes towards the development of fast opto-spintronic devices based on antiferromagnetic materials.
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Affiliation(s)
- E Rongione
- Unité Mixte de Physique, CNRS, Thales, Université Paris-Saclay, F-91767, Palaiseau, France
- Laboratoire de Physique de l'Ecole Normale Supérieure, ENS, Université PSL, CNRS, Sorbonne Université, Université Paris Cité, F-75005, Paris, France
| | - O Gueckstock
- Institute of Physics, Freie Universität Berlin, D-14195, Berlin, Germany
| | - M Mattern
- Institut für Physik und Astronomie, Universität Potsdam, D-14476, Potsdam, Germany
| | - O Gomonay
- Institute of Physics, Johannes Gutenberg-University Mainz, D-55099, Mainz, Germany
| | - H Meer
- Institute of Physics, Johannes Gutenberg-University Mainz, D-55099, Mainz, Germany
| | - C Schmitt
- Institute of Physics, Johannes Gutenberg-University Mainz, D-55099, Mainz, Germany
| | - R Ramos
- WPI-Advanced Institute for Materials Research, Tohoku University, Sendai, J-980-8577, Japan
- Centro Singular de Investigación en Química Bilóxica e Materiais Moleculares (CIQUS), Departamento de Química-Física, Universidade de Santiago de Compostela, Santiago de Compostela, 15782, Spain
| | - T Kikkawa
- Department of Applied Physics, The University of Tokyo, Tokyo, J-113-8656, Japan
| | - M Mičica
- Laboratoire de Physique de l'Ecole Normale Supérieure, ENS, Université PSL, CNRS, Sorbonne Université, Université Paris Cité, F-75005, Paris, France
| | - E Saitoh
- WPI-Advanced Institute for Materials Research, Tohoku University, Sendai, J-980-8577, Japan
- Department of Applied Physics, The University of Tokyo, Tokyo, J-113-8656, Japan
- Institute for AI and Beyond, The University of Tokyo, Tokyo, J-113-8656, Japan
| | - J Sinova
- Institute of Physics, Johannes Gutenberg-University Mainz, D-55099, Mainz, Germany
| | - H Jaffrès
- Unité Mixte de Physique, CNRS, Thales, Université Paris-Saclay, F-91767, Palaiseau, France
| | - J Mangeney
- Laboratoire de Physique de l'Ecole Normale Supérieure, ENS, Université PSL, CNRS, Sorbonne Université, Université Paris Cité, F-75005, Paris, France
| | - S T B Goennenwein
- Department of Physics, University of Konstanz, D-78457, Konstanz, Germany
| | - S Geprägs
- Walther-Meißner-Institut, Bayerische Akademie der Wissenschaften, D-85748, Garching, Germany
| | - T Kampfrath
- Institute of Physics, Freie Universität Berlin, D-14195, Berlin, Germany
| | - M Kläui
- Institute of Physics, Johannes Gutenberg-University Mainz, D-55099, Mainz, Germany
- Graduate School of Excellence Materials Science in Mainz (MAINZ), Staudingerweg 9, D-55128, Mainz, Germany
- Center for Quantum Spintronics, Department of Physics, Norwegian University of Science and Technology, N-7034, Trondheim, Norway
| | - M Bargheer
- Institut für Physik und Astronomie, Universität Potsdam, D-14476, Potsdam, Germany
- Helmholtz-Zentrum Berlin für Materialien und Energie, Wilhelm-Conrad-Röntgen Campus, BESSY II, Albert-Einstein-Strasse 15, D-12489, Berlin, Germany
| | - T S Seifert
- Institute of Physics, Freie Universität Berlin, D-14195, Berlin, Germany.
| | - S Dhillon
- Laboratoire de Physique de l'Ecole Normale Supérieure, ENS, Université PSL, CNRS, Sorbonne Université, Université Paris Cité, F-75005, Paris, France
| | - R Lebrun
- Unité Mixte de Physique, CNRS, Thales, Université Paris-Saclay, F-91767, Palaiseau, France.
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158
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Zhu L, Ralph DC. Strong variation of spin-orbit torques with relative spin relaxation rates in ferrimagnets. Nat Commun 2023; 14:1778. [PMID: 36997579 PMCID: PMC10063689 DOI: 10.1038/s41467-023-37506-9] [Citation(s) in RCA: 2] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Grants] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/28/2022] [Accepted: 03/20/2023] [Indexed: 04/03/2023] Open
Abstract
Spin-orbit torques (SOTs) have been widely understood as an interfacial transfer of spin that is independent of the bulk properties of the magnetic layer. Here, we report that SOTs acting on ferrimagnetic FexTb1-x layers decrease and vanish upon approaching the magnetic compensation point because the rate of spin transfer to the magnetization becomes much slower than the rate of spin relaxation into the crystal lattice due to spin-orbit scattering. These results indicate that the relative rates of competing spin relaxation processes within magnetic layers play a critical role in determining the strength of SOTs, which provides a unified understanding for the diverse and even seemingly puzzling SOT phenomena in ferromagnetic and compensated systems. Our work indicates that spin-orbit scattering within the magnet should be minimized for efficient SOT devices. We also find that the interfacial spin-mixing conductance of interfaces of ferrimagnetic alloys (such as FexTb1-x) is as large as that of 3d ferromagnets and insensitive to the degree of magnetic compensation.
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Affiliation(s)
- Lijun Zhu
- State Key Laboratory of Superlattices and Microstructures, Institute of Semiconductors, Chinese Academy of Sciences, Beijing, 100083, China.
- College of Materials Science and Opto-Electronic Technology, University of Chinese Academy of Sciences, Beijing, 100049, China.
| | - Daniel C Ralph
- Cornell University, Ithaca, NY, 14850, USA
- Kavli Institute at Cornell, Ithaca, NY, 14850, USA
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159
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Basak K, Ghosh M, Chowdhury S, Jana D. Theoretical studies on electronic, magnetic and optical properties of two dimensional transition metal trihalides. J Phys Condens Matter 2023; 35:233001. [PMID: 36854185 DOI: 10.1088/1361-648x/acbffb] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 09/29/2022] [Accepted: 02/28/2023] [Indexed: 06/18/2023]
Abstract
Two dimensional transition metal trihalides have drawn attention over the years due to their intrinsic ferromagnetism and associated large anisotropy at nanoscale. The interactions involved in these layered structures are of van der Waals types which are important for exfoliation to different thin samples. This enables one to compare the journey of physical properties from bulk structures to monolayer counterpart. In this topical review, the modulation of electronic, magnetic and optical properties by strain engineering, alloying, doping, defect engineering etc have been discussed extensively. The results obtained by first principle density functional theory calculations are verified by recent experimental observations. The relevant experimental synthesis of different morphological transition metal trihalides are highlighted. The feasibility of such routes may indicate other possible heterostructures. Apart from spintronics based applications, transition metal trihalides are potential candidates in sensing and data storage. Moreover, high thermoelectric figure of merit of chromium trihalides at higher temperatures leads to the possibility of multi-purpose applications. We hope this review will give important directions to further research in transition metal trihalide systems having tunable band gap with reduced dimensionalities.
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Affiliation(s)
- Krishnanshu Basak
- Department of Physics, University of Calcutta, 92 Acharya Prafulla Chandra Road, Kolkata 700009, India
| | - Mainak Ghosh
- Department of Physics, University of Calcutta, 92 Acharya Prafulla Chandra Road, Kolkata 700009, India
| | - Suman Chowdhury
- S.N. Bose National Centre for Basic Sciences, JD-III Salt Lake City, Kolkata 700098, India
- Department of Physics, Shiv Nadar University, Greater Noida, Uttar Pradesh 201314, India
| | - Debnarayan Jana
- Department of Physics, University of Calcutta, 92 Acharya Prafulla Chandra Road, Kolkata 700009, India
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160
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Ren H, Zheng XY, Channa S, Wu G, O'Mahoney DA, Suzuki Y, Kent AD. Hybrid spin Hall nano-oscillators based on ferromagnetic metal/ferrimagnetic insulator heterostructures. Nat Commun 2023; 14:1406. [PMID: 36918562 DOI: 10.1038/s41467-023-37028-4] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/02/2022] [Accepted: 03/01/2023] [Indexed: 03/16/2023] Open
Abstract
Spin-Hall nano-oscillators (SHNOs) are promising spintronic devices to realize current controlled GHz frequency signals in nanoscale devices for neuromorphic computing and creating Ising systems. However, traditional SHNOs devices based on transition metals have high auto-oscillation threshold currents as well as low quality factors and output powers. Here we demonstrate a new type of hybrid SHNO based on a permalloy (Py) ferromagnetic-metal nanowire and low-damping ferrimagnetic insulator, in the form of epitaxial lithium aluminum ferrite (LAFO) thin films. The superior characteristics of such SHNOs are associated with the excitation of larger spin-precession angles and volumes. We further find that the presence of the ferrimagnetic insulator enhances the auto-oscillation amplitude of spin-wave edge modes, consistent with our micromagnetic modeling. This hybrid SHNO expands spintronic applications, including providing new means of coupling multiple SHNOs for neuromorphic computing and advancing magnonics.
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161
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Paquelet Wuetz B, Degli Esposti D, Zwerver AJ, Amitonov SV, Botifoll M, Arbiol J, Vandersypen LMK, Russ M, Scappucci G. Reducing charge noise in quantum dots by using thin silicon quantum wells. Nat Commun 2023; 14:1385. [PMID: 36914637 DOI: 10.1038/s41467-023-36951-w] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/30/2022] [Accepted: 02/25/2023] [Indexed: 03/16/2023] Open
Abstract
Charge noise in the host semiconductor degrades the performance of spin-qubits and poses an obstacle to control large quantum processors. However, it is challenging to engineer the heterogeneous material stack of gate-defined quantum dots to improve charge noise systematically. Here, we address the semiconductor-dielectric interface and the buried quantum well of a 28Si/SiGe heterostructure and show the connection between charge noise, measured locally in quantum dots, and global disorder in the host semiconductor, measured with macroscopic Hall bars. In 5 nm thick 28Si quantum wells, we find that improvements in the scattering properties and uniformity of the two-dimensional electron gas over a 100 mm wafer correspond to a significant reduction in charge noise, with a minimum value of 0.29 ± 0.02 μeV/Hz½ at 1 Hz averaged over several quantum dots. We extrapolate the measured charge noise to simulated dephasing times to CZ-gate fidelities that improve nearly one order of magnitude. These results point to a clean and quiet crystalline environment for integrating long-lived and high-fidelity spin qubits into a larger system.
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162
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Meng Y, Jiang L, Zheng Y. Spin filters based on two-dimensional materials Co 2Si and Cu 2Si. J Phys Condens Matter 2023; 35:195001. [PMID: 36863029 DOI: 10.1088/1361-648x/acc0c0] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 12/03/2022] [Accepted: 03/02/2023] [Indexed: 02/17/2024]
Abstract
Spintronic devices have several advantages compared with conventional electronic devices, including non-volatility, faster data processing speed, higher integration densities, less electric power consumption and so on. However, we still face challenges for efficiently generating and injecting pure spin polarized current. In this work, we utilize two kinds of two-dimensional materials Co2Si and Cu2Si with both lattice match and band match to construct devices and then research their spin filter efficiency. The spin filter efficiency can be improved effectively either by an appropriate gate voltage at Co2Si region, or by series connection. In both cases the filter efficiencies are much larger than two-dimensional prepared Fe3GeTe2spin valve and ferromagnetic metallic chairlike O-graphene-H. Also at a quite small bias, we obtain a comparable spin polarized current as those obtained in Fe3GeTe2spin valve and O-graphene-H obtained at a much larger bias.
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Affiliation(s)
- Yexuan Meng
- Key Laboratory of Physics and Technology for Advanced Batteries (Ministry of Education), College of Physics, Jilin University, Changchun 130012, People's Republic of China
| | - Liwei Jiang
- Key Laboratory of Physics and Technology for Advanced Batteries (Ministry of Education), College of Physics, Jilin University, Changchun 130012, People's Republic of China
| | - Yisong Zheng
- Key Laboratory of Physics and Technology for Advanced Batteries (Ministry of Education), College of Physics, Jilin University, Changchun 130012, People's Republic of China
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163
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Yang S, Son JW, Ju TS, Tran DM, Han HS, Park S, Park BH, Moon KW, Hwang C. Magnetic Skyrmion Transistor Gated with Voltage-Controlled Magnetic Anisotropy. Adv Mater 2023; 35:e2208881. [PMID: 36511234 DOI: 10.1002/adma.202208881] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 09/27/2022] [Revised: 11/27/2022] [Indexed: 06/17/2023]
Abstract
The paradigm shift of information carriers from charge to spin has long been awaited in modern electronics. The invention of the spin-information transistor is expected to be an essential building block for the future development of spintronics. Here, a proof-of-concept experiment of a magnetic skyrmion transistor working at room temperature, which has never been demonstrated experimentally, is introduced. With the spatially uniform control of magnetic anisotropy, the shape and topology of a skyrmion when passing the controlled area can be maintained. The findings will open a new route toward the design and realization of skyrmion-based spintronic devices in the near future.
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Affiliation(s)
- Seungmo Yang
- Quantum Spin Team, Korea Research Institute of Standards and Science, Daejeon, 34113, Republic of Korea
| | - Jong Wan Son
- Quantum Spin Team, Korea Research Institute of Standards and Science, Daejeon, 34113, Republic of Korea
| | - Tae-Seong Ju
- Quantum Spin Team, Korea Research Institute of Standards and Science, Daejeon, 34113, Republic of Korea
- Department of Physics, Pusan National University, Busan, 46241, Republic of Korea
| | - Duc Minh Tran
- Division of Quantum Phases and Devices, Department of Physics, Konkuk University, Seoul, 05029, Republic of Korea
| | - Hee-Sung Han
- Department of Materials Science and Engineering, Ulsan National Institute of Science and Technology (UNIST), Ulsan, 44919, Republic of Korea
| | - Sungkyun Park
- Department of Physics, Pusan National University, Busan, 46241, Republic of Korea
| | - Bae Ho Park
- Division of Quantum Phases and Devices, Department of Physics, Konkuk University, Seoul, 05029, Republic of Korea
| | - Kyoung-Woong Moon
- Quantum Spin Team, Korea Research Institute of Standards and Science, Daejeon, 34113, Republic of Korea
| | - Chanyong Hwang
- Quantum Spin Team, Korea Research Institute of Standards and Science, Daejeon, 34113, Republic of Korea
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164
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Zhou B, Khanal P, Benally OJ, Lyu D, Gopman DB, Enriquez A, Habiboglu A, Warrilow K, Wang JP, Wang WG. Perpendicular magnetic anisotropy, tunneling magnetoresistance and spin-transfer torque effect in magnetic tunnel junctions with Nb layers. Sci Rep 2023; 13:3454. [PMID: 36859656 DOI: 10.1038/s41598-023-29752-0] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/05/2022] [Accepted: 02/09/2023] [Indexed: 03/03/2023] Open
Abstract
Nb and its compounds are widely used in quantum computing due to their high superconducting transition temperatures and high critical fields. Devices that combine superconducting performance and spintronic non-volatility could deliver unique functionality. Here we report the study of magnetic tunnel junctions with Nb as the heavy metal layers. An interfacial perpendicular magnetic anisotropy energy density of 1.85 mJ/m2 was obtained in Nb/CoFeB/MgO heterostructures. The tunneling magnetoresistance was evaluated in junctions with different thickness combinations and different annealing conditions. An optimized magnetoresistance of 120% was obtained at room temperature, with a damping parameter of 0.011 determined by ferromagnetic resonance. In addition, spin-transfer torque switching has also been successfully observed in these junctions with a quasistatic switching current density of 7.3 [Formula: see text] A/cm2.
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165
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Oh DG, Kim JH, Kim MK, Jeong KW, Shin HJ, Hong JM, Kim JS, Moon K, Lee N, Choi YJ. Spin-flip-driven anomalous Hall effect and anisotropic magnetoresistance in a layered Ising antiferromagnet. Sci Rep 2023; 13:3391. [PMID: 36854958 DOI: 10.1038/s41598-023-30076-2] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [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.
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166
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Yang J, Gao B, Liu W, Du J, Xu Q. Supercritical CO 2 -induced New Chemical Bond of C-O-Si in Graphdiyne to Achieve Robust Room-Temperature Ferromagnetism. Chemphyschem 2023; 24:e202200793. [PMID: 36806422 DOI: 10.1002/cphc.202200793] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/22/2022] [Revised: 02/09/2023] [Accepted: 02/13/2023] [Indexed: 02/21/2023]
Abstract
The realization of ferromagnetic ordering of two-dimensional (2D) carbon material graphdiyne (GDY) has attracted great attention due to its promising application in spin semiconductor devices. However, the absence of localized spins makes the pristine GDY intrinsically nonferromagnetic. Herein, we report the realization of robust room-temperature (RT) ferromagnetism (FM) with Curie temperature (TC ) up to 325 K for GDY Nanosheets (GDYNs) by supercritical CO2 (SC CO2 ). Experimental and theoretical calculations reveal that the new chemical bond of C-O-Si can be formed because of the unique effect of SC CO2 , which help to enhance the charge transfer and generates long-range ferromagnetic order. The RT saturation magnetization (MS ) reaches 1.125 emu/g, which is much higher than that of carbon-based materials reported up to now. Meanwhile, by changing the conditions of SC CO2 such as pressure, ferromagnetic responses can be manipulated, which is great for potential spintronics applications of GDY.
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Affiliation(s)
- Jian Yang
- Henan Institute of Advanced Technology, Zhengzhou University, Zhengzhou, 450052, P. R. China
| | - Bo Gao
- College of Materials Science and Engineering, Zhengzhou University, Zhengzhou, 450052, P. R. China
| | - Wei Liu
- Henan Institute of Advanced Technology, Zhengzhou University, Zhengzhou, 450052, P. R. China
| | - Jiang Du
- College of Materials Science and Engineering, Zhengzhou University, Zhengzhou, 450052, P. R. China
| | - Qun Xu
- Henan Institute of Advanced Technology, Zhengzhou University, Zhengzhou, 450052, P. R. China.,College of Materials Science and Engineering, Zhengzhou University, Zhengzhou, 450052, P. R. China
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167
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Chen JS, Trerayapiwat KJ, Sun L, Krzyaniak MD, Wasielewski MR, Rajh T, Sharifzadeh S, Ma X. Long-lived electronic spin qubits in single-walled carbon nanotubes. Nat Commun 2023; 14:848. [PMID: 36792597 DOI: 10.1038/s41467-023-36031-z] [Citation(s) in RCA: 3] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [Key Words] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/24/2022] [Accepted: 01/12/2023] [Indexed: 02/17/2023] Open
Abstract
Electron spins in solid-state systems offer the promise of spin-based information processing devices. Single-walled carbon nanotubes (SWCNTs), an all-carbon one-dimensional material whose spin-free environment and weak spin-orbit coupling promise long spin coherence times, offer a diverse degree of freedom for extended range of functionality not available to bulk systems. A key requirement limiting spin qubit implementation in SWCNTs is disciplined confinement of isolated spins. Here, we report the creation of highly confined electron spins in SWCNTs via a bottom-up approach. The record long coherence time of 8.2 µs and spin-lattice relaxation time of 13 ms of these electronic spin qubits allow demonstration of quantum control operation manifested as Rabi oscillation. Investigation of the decoherence mechanism reveals an intrinsic coherence time of tens of milliseconds. These findings evident that combining molecular approaches with inorganic crystalline systems provides a powerful route for reproducible and scalable quantum materials suitable for qubit applications.
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168
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Goel S, Khang NHD, Osada Y, Anh LD, Hai PN, Tanaka M. Room-temperature spin injection from a ferromagnetic semiconductor. Sci Rep 2023; 13:2181. [PMID: 36750728 PMCID: PMC9905071 DOI: 10.1038/s41598-023-29169-9] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Grants] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/27/2022] [Accepted: 01/31/2023] [Indexed: 02/09/2023] Open
Abstract
Spin injection using ferromagnetic semiconductors at room temperature is a building block for the realization of spin-functional semiconductor devices. Nevertheless, this has been very challenging due to the lack of reliable room-temperature ferromagnetism in well-known group IV and III-V based semiconductors. Here, we demonstrate room-temperature spin injection by using spin pumping in a BiSb/(Ga,Fe)Sb heterostructure, where (Ga,Fe)Sb is a ferromagnetic semiconductor (FMS) with high Curie temperature (TC) and BiSb is a topological insulator (TI). Despite the very small magnetization of (Ga,Fe)Sb at room temperature (45 emu/cc), we detected spin injection from (Ga,Fe)Sb by utilizing the large inverse spin Hall effect (ISHE) in BiSb. Our study provides the first demonstration of spin injection at room temperature from a FMS.
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Affiliation(s)
- Shobhit Goel
- Department of Electrical Engineering and Information Systems, The University of Tokyo, 7-3-1 Hongo, Bunkyo-ku, Tokyo, 113-8656, Japan.
- CREST, Japan Science and Technology Agency, 4-1-8 Honcho, Kawaguchi, Saitama, 332-0012, Japan.
| | - Nguyen Huynh Duy Khang
- Department of Electrical and Electronic Engineering, Tokyo Institute of Technology, 2-12-1 Ookayama, Meguro-ku, Tokyo, 152-8550, Japan
- Department of Physics, Ho Chi Minh City University of Education, 280 An Duong Vuong Street, District 5, Ho Chi Minh City, 738242, Vietnam
| | - Yuki Osada
- Department of Electrical and Electronic Engineering, Tokyo Institute of Technology, 2-12-1 Ookayama, Meguro-ku, Tokyo, 152-8550, Japan
| | - Le Duc Anh
- Department of Electrical Engineering and Information Systems, The University of Tokyo, 7-3-1 Hongo, Bunkyo-ku, Tokyo, 113-8656, Japan
- Institute of Engineering Innovation, The University of Tokyo, 7-3-1 Hongo, Bunkyo-ku, Tokyo, 113-8656, Japan
- PRESTO, Japan Science and Technology Agency, 4-1-8 Honcho, Kawaguchi, Saitama, 332-0012, Japan
- Center for Spintronics Research Network (CSRN), The University of Tokyo, 7-3-1 Hongo, Bunkyo-ku, Tokyo, 113-8656, Japan
| | - Pham Nam Hai
- CREST, Japan Science and Technology Agency, 4-1-8 Honcho, Kawaguchi, Saitama, 332-0012, Japan.
- Department of Electrical and Electronic Engineering, Tokyo Institute of Technology, 2-12-1 Ookayama, Meguro-ku, Tokyo, 152-8550, Japan.
- Center for Spintronics Research Network (CSRN), The University of Tokyo, 7-3-1 Hongo, Bunkyo-ku, Tokyo, 113-8656, Japan.
| | - Masaaki Tanaka
- Department of Electrical Engineering and Information Systems, The University of Tokyo, 7-3-1 Hongo, Bunkyo-ku, Tokyo, 113-8656, Japan.
- CREST, Japan Science and Technology Agency, 4-1-8 Honcho, Kawaguchi, Saitama, 332-0012, Japan.
- Center for Spintronics Research Network (CSRN), The University of Tokyo, 7-3-1 Hongo, Bunkyo-ku, Tokyo, 113-8656, Japan.
- Institute for Nano Quantum Information Electronics, The University of Tokyo, 4-6-1 Komaba, Meguro-ku, Tokyo, 153-8505, Japan.
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169
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Miyazaki Y, Yokouchi T, Shiomi Y. Trapping and manipulating skyrmions in two-dimensional films by surface acoustic waves. Sci Rep 2023; 13:1922. [PMID: 36732549 PMCID: PMC9895437 DOI: 10.1038/s41598-023-29022-z] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/22/2022] [Accepted: 01/30/2023] [Indexed: 02/04/2023] Open
Abstract
Skyrmions, topologically stable spin structures with particle-like properties, are promising for spintronics applications such as skyrmion racetrack memory. Though reliable control of skyrmion motion is essential for the operation of spintronics devices, the straight motion of skyrmions along the driving force is in general difficult due to an inevitable transverse force originating from their topology. Here, we propose a method of precise manipulation of skyrmions based on surface acoustic waves (SAWs) propagating in two dimensions. Using two standing SAWs, saddle-shape local potentials like quadrupole ion traps are created to trap skyrmions robustly. Furthermore, by tuning the frequencies of the SAWs, we show that trapped skyrmions not only move in straight lines but also move precisely in any direction in a two-dimensional thin film. These results could be helpful for the future design of spintronics devices based on skyrmions.
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Affiliation(s)
- Yu Miyazaki
- grid.26999.3d0000 0001 2151 536XDepartment of Applied Physics, The University of Tokyo, Hongo, Bunkyo, Tokyo 113-8656 Japan
| | - Tomoyuki Yokouchi
- grid.26999.3d0000 0001 2151 536XDepartment of Basic Science, The University of Tokyo, Komaba, Meguro, Tokyo 153-8902 Japan
| | - Yuki Shiomi
- grid.26999.3d0000 0001 2151 536XDepartment of Basic Science, The University of Tokyo, Komaba, Meguro, Tokyo 153-8902 Japan
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170
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Deng Y, Liu X, Chen Y, Du Z, Jiang N, Shen C, Zhang E, Zheng H, Lu HZ, Wang K. All-electrical switching of a topological non-collinear antiferromagnet at room temperature. Natl Sci Rev 2023; 10:nwac154. [PMID: 36872930 PMCID: PMC9977383 DOI: 10.1093/nsr/nwac154] [Citation(s) in RCA: 7] [Impact Index Per Article: 7.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/15/2022] [Accepted: 07/31/2022] [Indexed: 11/14/2022] Open
Abstract
Non-collinear antiferromagnetic Weyl semimetals, combining the advantages of a zero stray field and ultrafast spin dynamics, as well as a large anomalous Hall effect and the chiral anomaly of Weyl fermions, have attracted extensive interest. However, the all-electrical control of such systems at room temperature, a crucial step toward practical application, has not been reported. Here, using a small writing current density of around 5 × 106 A·cm-2, we realize the all-electrical current-induced deterministic switching of the non-collinear antiferromagnet Mn3Sn, with a strong readout signal at room temperature in the Si/SiO2/Mn3Sn/AlOx structure, and without external magnetic field or injected spin current. Our simulations reveal that the switching originates from the current-induced intrinsic non-collinear spin-orbit torques in Mn3Sn itself. Our findings pave the way for the development of topological antiferromagnetic spintronics.
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Affiliation(s)
- Yongcheng Deng
- State Key Laboratory for Superlattices and Microstructures, Institute of Semiconductors, Chinese Academy of Sciences, Beijing 100083, China.,Center of Materials Science and Optoelectronics Engineering, University of Chinese Academy of Sciences, Beijing 100049, China
| | - Xionghua Liu
- State Key Laboratory for Superlattices and Microstructures, Institute of Semiconductors, Chinese Academy of Sciences, Beijing 100083, China.,Center of Materials Science and Optoelectronics Engineering, University of Chinese Academy of Sciences, Beijing 100049, China
| | - Yiyuan Chen
- Institute for Quantum Science and Engineering and Department of Physics, Southern University of Science and Technology (SUSTech), Shenzhen 518055, China.,International Quantum Academy, Shenzhen 518048, China
| | - Zongzheng Du
- Institute for Quantum Science and Engineering and Department of Physics, Southern University of Science and Technology (SUSTech), Shenzhen 518055, China.,International Quantum Academy, Shenzhen 518048, China
| | - Nai Jiang
- State Key Laboratory for Superlattices and Microstructures, Institute of Semiconductors, Chinese Academy of Sciences, Beijing 100083, China.,Center of Materials Science and Optoelectronics Engineering, University of Chinese Academy of Sciences, Beijing 100049, China
| | - Chao Shen
- State Key Laboratory for Superlattices and Microstructures, Institute of Semiconductors, Chinese Academy of Sciences, Beijing 100083, China.,Center of Materials Science and Optoelectronics Engineering, University of Chinese Academy of Sciences, Beijing 100049, China
| | - Enze Zhang
- State Key Laboratory for Superlattices and Microstructures, Institute of Semiconductors, Chinese Academy of Sciences, Beijing 100083, China.,Center of Materials Science and Optoelectronics Engineering, University of Chinese Academy of Sciences, Beijing 100049, China
| | - Houzhi Zheng
- State Key Laboratory for Superlattices and Microstructures, Institute of Semiconductors, Chinese Academy of Sciences, Beijing 100083, China.,Center of Materials Science and Optoelectronics Engineering, University of Chinese Academy of Sciences, Beijing 100049, China
| | - Hai-Zhou Lu
- Institute for Quantum Science and Engineering and Department of Physics, Southern University of Science and Technology (SUSTech), Shenzhen 518055, China.,International Quantum Academy, Shenzhen 518048, China
| | - Kaiyou Wang
- State Key Laboratory for Superlattices and Microstructures, Institute of Semiconductors, Chinese Academy of Sciences, Beijing 100083, China.,Center of Materials Science and Optoelectronics Engineering, University of Chinese Academy of Sciences, Beijing 100049, China.,Beijing Academy of Quantum Information Sciences, Beijing 100193, China.,Center for Excellence in Topological Quantum Computation, University of Chinese Academy of Sciences, Beijing 100049, China
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171
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Zhu Y, Jiang Q, Zhang J, Ma Y. Recent Progress of Organic Semiconductor Materials in Spintronics. Chem Asian J 2023; 18:e202201125. [PMID: 36510771 DOI: 10.1002/asia.202201125] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/07/2022] [Revised: 12/12/2022] [Accepted: 12/12/2022] [Indexed: 12/15/2022]
Abstract
Spintronics, a new discipline focusing on the spin-dependent transport process of electrons, has been developing rapidly. Spin valves are the most significant carriers of spintronics utilizing the spin freedom of electrons. It is expected to pierce "Moore's Law" and become the core component in processors of the next generation. Organic semiconductors advance in their adjustable band gap, weak spin-orbit coupling and hyperfine interaction, excellent film-forming property, having enormous promise for spin valves. Here, the principle of spin valves is introduced, and the history and progress in organic spin injection and transport materials are summarized. Then we analyze the influence of spinterface on device performance and introduce reliable methods of constructing organic spin valves. Finally, the challenges for spin valves are discussed, and the future is proposed. We aim to draw the attention of researchers to organic spin valves and promote further research in spintronics through this paper.
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Affiliation(s)
- Yanuo Zhu
- Institute of Polymer Optoelectronic Materials and Devices, State Key Laboratory of Luminescent Materials and Devices, South China University of Technology, 381 Wushan Road, Guangzhou, Guangdong, 510640, P. R. China
| | - Qinglin Jiang
- Institute of Polymer Optoelectronic Materials and Devices, State Key Laboratory of Luminescent Materials and Devices, South China University of Technology, 381 Wushan Road, Guangzhou, Guangdong, 510640, P. R. China
| | - Jiang Zhang
- Department of Physics, South China University of Technology 381 Wushan Road, Guangzhou, Guangdong, 510640, P. R. China
| | - Yuguang Ma
- Institute of Polymer Optoelectronic Materials and Devices, State Key Laboratory of Luminescent Materials and Devices, South China University of Technology, 381 Wushan Road, Guangzhou, Guangdong, 510640, P. R. China
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172
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Kholid FN, Hamara D, Hamdan AFB, Nava Antonio G, Bowen R, Petit D, Cowburn R, Pisarev RV, Bossini D, Barker J, Ciccarelli C. The importance of the interface for picosecond spin pumping in antiferromagnet-heavy metal heterostructures. Nat Commun 2023; 14:538. [PMID: 36725847 DOI: 10.1038/s41467-023-36166-z] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/17/2022] [Accepted: 01/19/2023] [Indexed: 02/03/2023] Open
Abstract
Interfaces in heavy metal (HM) - antiferromagnetic insulator (AFI) heterostructures have recently become highly investigated and debated systems in the effort to create spintronic devices that function at terahertz frequencies. Such heterostructures have great technological potential because AFIs can generate sub-picosecond spin currents which the HMs can convert into charge signals. In this work we demonstrate an optically induced picosecond spin transfer at the interface between AFIs and Pt using time-domain THz emission spectroscopy. We select two antiferromagnets in the same family of fluoride cubic perovskites, KCoF3 and KNiF3, whose magnon frequencies at the centre of the Brillouin zone differ by an order of magnitude. By studying their behaviour with temperature, we correlate changes in the spin transfer efficiency across the interface to the opening of a gap in the magnon density of states below the Néel temperature. Our observations are reproduced in a model based on the spin exchange between the localized electrons in the antiferromagnet and the free electrons in Pt. Through this comparative study of selected materials, we are able to shine light on the microscopy of spin transfer at picosecond timescales between antiferromagnets and heavy metals and identify a key figure of merit for its efficiency: the magnon gap. Our results are important for progressing in the fundamental understanding of the highly discussed physics of the HM/AFI interfaces, which is the necessary cornerstone for the designing of femtosecond antiferromagnetic spintronics devices with optimized characteristics.
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173
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Zhang W, Huang TX, Hehn M, Malinowski G, Verges M, Hohlfeld J, Remy Q, Lacour D, Wang XR, Zhao GP, Vallobra P, Xu Y, Mangin S, Zhao WS. Optical Creation of Skyrmions by Spin Reorientation Transition in Ferrimagnetic CoHo Alloys. ACS Appl Mater Interfaces 2023; 15:5608-5619. [PMID: 36689950 DOI: 10.1021/acsami.2c19411] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/17/2023]
Abstract
Manipulating magnetic skyrmions by means of a femtosecond (fs) laser pulse has attracted great interest due to their promising applications in efficient information-storage devices with ultralow energy consumption. However, the mechanism underlying the creation of skyrmions induced by an fs laser is still lacking. As a result, a key challenge is to reveal the pathway for the massive reorientation of magnetization from trivial to nontrivial topological states. Here, we studied a series of ferrimagnetic CoHo alloys and investigated the effect of a single laser pulse on the magnetic states. Thanks to the time-resolved magneto-optical Kerr effect and imaging techniques, we demonstrate that the laser-induced phase transitions from single domains into a topological skyrmion phase are mediated by the transient in-plane magnetization state, in real time and space domains, respectively. Combining experiments and micromagnetic simulations, we propose a two-step process for creating skyrmions through laser pulse irradiation: (i) the electron temperature enhancement induces a spin reorientation transition on a picosecond (ps) timescale due to the suppression of perpendicular magnetic anisotropy (PMA) and (ii) the PMA slowly restores, accompanied by out-of-plane magnetization recovery, leading to the generation of skyrmions with the help of spin fluctuations. This work provides a route to control skyrmion patterns using an fs laser, thereby establishing the foundation for further exploration of topological magnetism at ultrafast timescales.
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Affiliation(s)
- Wei Zhang
- Anhui High Reliability Chips Engineering Laboratory, Hefei Innovation Research Institute, Beihang University, Hefei230013, China
- MIIT Key Laboratory of Spintronics, School of Integrated Circuit Science and Engineering, Beihang University, Beijing100191, China
- CNRS, IJL, Université de Lorraine, NancyF-54000, France
| | | | - Michel Hehn
- CNRS, IJL, Université de Lorraine, NancyF-54000, France
| | | | - Maxime Verges
- CNRS, IJL, Université de Lorraine, NancyF-54000, France
| | | | - Quentin Remy
- CNRS, IJL, Université de Lorraine, NancyF-54000, France
| | - Daniel Lacour
- CNRS, IJL, Université de Lorraine, NancyF-54000, France
| | - Xin Ran Wang
- MIIT Key Laboratory of Spintronics, School of Integrated Circuit Science and Engineering, Beihang University, Beijing100191, China
| | - Guo Ping Zhao
- College of Physics and Electronic Engineering and Institute of Solid State Physics, Sichuan Normal University, Chengdu610066, China
| | - Pierre Vallobra
- Anhui High Reliability Chips Engineering Laboratory, Hefei Innovation Research Institute, Beihang University, Hefei230013, China
| | - Yong Xu
- Anhui High Reliability Chips Engineering Laboratory, Hefei Innovation Research Institute, Beihang University, Hefei230013, China
- MIIT Key Laboratory of Spintronics, School of Integrated Circuit Science and Engineering, Beihang University, Beijing100191, China
| | | | - Wei Sheng Zhao
- Anhui High Reliability Chips Engineering Laboratory, Hefei Innovation Research Institute, Beihang University, Hefei230013, China
- MIIT Key Laboratory of Spintronics, School of Integrated Circuit Science and Engineering, Beihang University, Beijing100191, China
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174
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Mertens F, Mönkebüscher D, Parlak U, Boix-Constant C, Mañas-Valero S, Matzer M, Adhikari R, Bonanni A, Coronado E, Kalashnikova AM, Bossini D, Cinchetti M. Ultrafast Coherent THz Lattice Dynamics Coupled to Spins in the van der Waals Antiferromagnet FePS 3. Adv Mater 2023; 35:e2208355. [PMID: 36437480 DOI: 10.1002/adma.202208355] [Citation(s) in RCA: 5] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 09/12/2022] [Revised: 11/18/2022] [Indexed: 06/16/2023]
Abstract
Coherent THz optical lattice and hybridized phonon-magnon modes are triggered by femtosecond laser pulses in the antiferromagnetic van der Waals semiconductor FePS3 . The laser-driven lattice and spin dynamics are investigated in a bulk crystal as well as in a 380 nm-thick exfoliated flake as a function of the excitation photon energy, sample temperature and applied magnetic field. The pump-probe magneto-optical measurements reveal that the amplitude of a coherent phonon mode oscillating at 3.2 THz decreases as the sample is heated up to the Néel temperature. This signal eventually vanishes as the phase transition to the paramagnetic phase occurs, thus revealing its connection to the long-range magnetic order. In the presence of an external magnetic field, the optically triggered 3.2 THz phonon hybridizes with a magnon mode, which is utilized to excite the hybridized phonon-magnon mode optically. These findings open a pathway toward the optical control of coherent THz photo-magnonic dynamics in a van der Waals antiferromagnet, which can be scaled down to the 2D limit.
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Affiliation(s)
- Fabian Mertens
- Department of Physics, TU Dortmund University, Otto-Hahn Straße 4, 44227, Dortmund, Germany
| | - David Mönkebüscher
- Department of Physics, TU Dortmund University, Otto-Hahn Straße 4, 44227, Dortmund, Germany
| | - Umut Parlak
- Department of Physics, TU Dortmund University, Otto-Hahn Straße 4, 44227, Dortmund, Germany
| | - Carla Boix-Constant
- Instituto de Ciencia Molecular (ICMol) Universidad de Valencia, Catedrático José Beltrán 2, Paterna, 46890, Spain
| | - Samuel Mañas-Valero
- Instituto de Ciencia Molecular (ICMol) Universidad de Valencia, Catedrático José Beltrán 2, Paterna, 46890, Spain
| | - Margherita Matzer
- Institute of Semiconductor and Solid State Physics, Johannes Kepler University Linz, Altenbergerstr. 69, Linz, 4040, Austria
| | - Rajdeep Adhikari
- Institute of Semiconductor and Solid State Physics, Johannes Kepler University Linz, Altenbergerstr. 69, Linz, 4040, Austria
| | - Alberta Bonanni
- Institute of Semiconductor and Solid State Physics, Johannes Kepler University Linz, Altenbergerstr. 69, Linz, 4040, Austria
| | - Eugenio Coronado
- Instituto de Ciencia Molecular (ICMol) Universidad de Valencia, Catedrático José Beltrán 2, Paterna, 46890, Spain
| | | | - Davide Bossini
- Department of Physics, TU Dortmund University, Otto-Hahn Straße 4, 44227, Dortmund, Germany
- Department of Physics and Center for Applied Photonics, University of Konstanz, D-78457, Konstanz, Germany
| | - Mirko Cinchetti
- Department of Physics, TU Dortmund University, Otto-Hahn Straße 4, 44227, Dortmund, Germany
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175
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Carmiggelt JJ, Bertelli I, Mulder RW, Teepe A, Elyasi M, Simon BG, Bauer GEW, Blanter YM, van der Sar T. Broadband microwave detection using electron spins in a hybrid diamond-magnet sensor chip. Nat Commun 2023; 14:490. [PMID: 36717574 DOI: 10.1038/s41467-023-36146-3] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/18/2022] [Accepted: 01/18/2023] [Indexed: 01/31/2023] Open
Abstract
Quantum sensing has developed into a main branch of quantum science and technology. It aims at measuring physical quantities with high resolution, sensitivity, and dynamic range. Electron spins in diamond are powerful magnetic field sensors, but their sensitivity in the microwave regime is limited to a narrow band around their resonance frequency. Here, we realize broadband microwave detection using spins in diamond interfaced with a thin-film magnet. A pump field locally converts target microwave signals to the sensor-spin frequency via the non-linear spin-wave dynamics of the magnet. Two complementary conversion protocols enable sensing and high-fidelity spin control over a gigahertz bandwidth, allowing characterization of the spin-wave band at multiple gigahertz above the sensor-spin frequency. The pump-tunable, hybrid diamond-magnet sensor chip opens the way for spin-based gigahertz material characterizations at small magnetic bias fields.
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176
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Remy Q, Hohlfeld J, Vergès M, Le Guen Y, Gorchon J, Malinowski G, Mangin S, Hehn M. Accelerating ultrafast magnetization reversal by non-local spin transfer. Nat Commun 2023; 14:445. [PMID: 36707525 PMCID: PMC9883451 DOI: 10.1038/s41467-023-36164-1] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/07/2022] [Accepted: 01/19/2023] [Indexed: 01/29/2023] Open
Abstract
When exciting a magnetic material with a femtosecond laser pulse, the amplitude of magnetization is no longer constant and can decrease within a time scale comparable to the duration of the optical excitation. This ultrafast demagnetization can even trigger an ultrafast, out of equilibrium, phase transition to a paramagnetic state. The reciprocal effect, namely an ultrafast remagnetization from the zero magnetization state, is a necessary ingredient to achieve a complete ultrafast reversal. However, the speed of remagnetization is limited by the universal critical slowing down which appears close to a phase transition. Here we demonstrate that magnetization can be reversed in a few hundreds of femtoseconds by overcoming the critical slowing down thanks to ultrafast spin cooling and spin heating mechanisms. We foresee that these results outline the potential of ultrafast spintronics for future ultrafast and energy efficient magnetic memory and storage devices. Furthermore, this should motivate further theoretical works in the field of femtosecond magnetization reversal.
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Affiliation(s)
- Quentin Remy
- grid.461892.00000 0000 9407 7201Université de Lorraine, Institut Jean Lamour, UMR, 7198 CNRS Nancy, France
| | - Julius Hohlfeld
- grid.461892.00000 0000 9407 7201Université de Lorraine, Institut Jean Lamour, UMR, 7198 CNRS Nancy, France
| | - Maxime Vergès
- grid.461892.00000 0000 9407 7201Université de Lorraine, Institut Jean Lamour, UMR, 7198 CNRS Nancy, France
| | - Yann Le Guen
- grid.461892.00000 0000 9407 7201Université de Lorraine, Institut Jean Lamour, UMR, 7198 CNRS Nancy, France
| | - Jon Gorchon
- grid.461892.00000 0000 9407 7201Université de Lorraine, Institut Jean Lamour, UMR, 7198 CNRS Nancy, France
| | - Grégory Malinowski
- grid.461892.00000 0000 9407 7201Université de Lorraine, Institut Jean Lamour, UMR, 7198 CNRS Nancy, France
| | - Stéphane Mangin
- grid.461892.00000 0000 9407 7201Université de Lorraine, Institut Jean Lamour, UMR, 7198 CNRS Nancy, France
| | - Michel Hehn
- grid.461892.00000 0000 9407 7201Université de Lorraine, Institut Jean Lamour, UMR, 7198 CNRS Nancy, France
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177
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Gruszecki P, Kisielewski J. Influence of Dzyaloshinskii-Moriya interaction and perpendicular anisotropy on spin waves propagation in stripe domain patterns and spin spirals. Sci Rep 2023; 13:1218. [PMID: 36681720 PMCID: PMC9867791 DOI: 10.1038/s41598-023-28271-2] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/21/2022] [Accepted: 01/16/2023] [Indexed: 01/22/2023] Open
Abstract
Texture-based magnonics focuses on the utilization of spin waves in magnetization textures to process information. Using micromagnetic simulations, we study how (1) the dynamic magnetic susceptibility, (2) dispersion relations, and (3) the equilibrium magnetic configurations in periodic magnetization textures in a ultrathin ferromagnetic film in remanence depend on the values of the Dzyaloshinskii-Moriya interaction and the perpendicular magnetocrystalline anisotropy. We observe that for large Dzyaloshinskii-Moriya interaction values, spin spirals with periods of tens of nanometers are the preferred state; for small Dzyaloshinskii-Moriya interaction values and large anisotropies, stripe domain patterns with over a thousand times larger period are preferable. We observe and explain the selectivity of the excitation of resonant modes by a linearly polarized microwave field. We study the propagation of spin waves along and perpendicular to the direction of the periodicity. For propagation along the direction of the periodicity, we observe a bandgap that closes and reopens, which is accompanied by a swap in the order of the bands. For waves propagating in the perpendicular direction, some modes can be used for unidirectional channeling of spin waves. Overall, our findings are promising in sensing and signal processing applications and explain the fundamental properties of periodic magnetization textures.
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Affiliation(s)
- Pawel Gruszecki
- grid.5633.30000 0001 2097 3545Institute of Spintronics and Quantum Information, Faculty of Physics, Adam Mickiewicz University, Poznań, 61-712 Poland
| | - Jan Kisielewski
- grid.25588.320000 0004 0620 6106Faculty of Physics, University of Białystok, Białystok, 15-245 Poland
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178
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Sun W, Chen Y, Zhuang W, Chen Z, Song A, Liu R, Wang X. Sizable spin-to-charge conversion in PLD-grown amorphous (Mo, W)Te 2-xfilms. Nanotechnology 2023; 34:135001. [PMID: 36584386 DOI: 10.1088/1361-6528/acaf34] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 09/29/2022] [Accepted: 12/29/2022] [Indexed: 06/17/2023]
Abstract
We report on the spin-to-charge conversion (SCC) in Mo0.25W0.75Te2-x(MWT)/Y3Fe5O12(YIG) heterostructures at room temperature. The centimeter-scale amorphous MWT films are deposited on liquid-phase-epitaxial YIG by pulsed laser deposition technique. The significant SCC voltage is measured in the MWT layer with a sizable spin Hall angle of ∼0.021 by spin pumping experiments. The control experiments by inserting MgO or Ag layer between MWT and YIG show that the SCC is mainly attributed to the inverse spin Hall effect rather than the thermal or interfacial Rashba effect. Our work provides a novel spin-source material for energy-efficient topological spintronic devices.
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Affiliation(s)
- Wenxuan Sun
- Jiangsu Provincial Key Laboratory of Advanced Photonic and Electronic Materials, School of Electronic Science and Engineering, Collaborative Innovation Center of Advanced Microstructures, Nanjing University, Nanjing 210093, People's Republic of China
| | - Yequan Chen
- Jiangsu Provincial Key Laboratory of Advanced Photonic and Electronic Materials, School of Electronic Science and Engineering, Collaborative Innovation Center of Advanced Microstructures, Nanjing University, Nanjing 210093, People's Republic of China
| | - Wenzhuo Zhuang
- Jiangsu Provincial Key Laboratory of Advanced Photonic and Electronic Materials, School of Electronic Science and Engineering, Collaborative Innovation Center of Advanced Microstructures, Nanjing University, Nanjing 210093, People's Republic of China
| | - Zhongqiang Chen
- Jiangsu Provincial Key Laboratory of Advanced Photonic and Electronic Materials, School of Electronic Science and Engineering, Collaborative Innovation Center of Advanced Microstructures, Nanjing University, Nanjing 210093, People's Republic of China
| | - Anke Song
- Jiangsu Provincial Key Laboratory of Advanced Photonic and Electronic Materials, School of Electronic Science and Engineering, Collaborative Innovation Center of Advanced Microstructures, Nanjing University, Nanjing 210093, People's Republic of China
| | - Ruxin Liu
- Jiangsu Provincial Key Laboratory of Advanced Photonic and Electronic Materials, School of Electronic Science and Engineering, Collaborative Innovation Center of Advanced Microstructures, Nanjing University, Nanjing 210093, People's Republic of China
| | - Xuefeng Wang
- Jiangsu Provincial Key Laboratory of Advanced Photonic and Electronic Materials, School of Electronic Science and Engineering, Collaborative Innovation Center of Advanced Microstructures, Nanjing University, Nanjing 210093, People's Republic of China
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179
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Chen W, Tang H, Wang Y, Hu X, Lin Y, Min T, Xie Y. E-Spin: A Stochastic Ising Spin Based on Electrically-Controlled MTJ for Constructing Large-Scale Ising Annealing Systems. Micromachines (Basel) 2023; 14:258. [PMID: 36837958 PMCID: PMC9962373 DOI: 10.3390/mi14020258] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 10/19/2022] [Revised: 01/01/2023] [Accepted: 01/14/2023] [Indexed: 06/18/2023]
Abstract
With its unique computer paradigm, the Ising annealing machine has become an emerging research direction. The Ising annealing system is highly effective at addressing combinatorial optimization (CO) problems that are difficult for conventional computers to tackle. However, Ising spins, which comprise the Ising system, are difficult to implement in high-performance physical circuits. We propose a novel type of Ising spin based on an electrically-controlled magnetic tunnel junction (MTJ). Electrical operation imparts true randomness, great stability, precise control, compact size, and easy integration to the MTJ-based spin. In addition, simulations demonstrate that the frequency of electrically-controlled stochastic Ising spin (E-spin) is 50 times that of the thermal disturbance MTJ-based spin (p-bit). To develop a large-scale Ising annealing system, up to 64 E-spins are implemented. Our Ising annealing system demonstrates factorization of integers up to 264 with a temporal complexity of around O(n). The proposed E-spin shows superiority in constructing large-scale Ising annealing systems and solving CO problems.
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Affiliation(s)
- Wenhan Chen
- State Key Laboratory of ASIC & System, School of Microelectronics, Fudan University, Shanghai 201203, China
| | - Haodi Tang
- State Key Laboratory of ASIC & System, School of Microelectronics, Fudan University, Shanghai 201203, China
| | - Yu Wang
- State Key Laboratory of ASIC & System, School of Microelectronics, Fudan University, Shanghai 201203, China
| | - Xianwu Hu
- State Key Laboratory of ASIC & System, School of Microelectronics, Fudan University, Shanghai 201203, China
| | - Yuming Lin
- State Key Laboratory of ASIC & System, School of Microelectronics, Fudan University, Shanghai 201203, China
| | - Tai Min
- Center for Spintronics and Quantum Systems, State Key Laboratory for Mechanical Behavior of Materials, Department of Materials Science and Engineering, Xi’an Jiaotong University, Xi’an 710049, China
| | - Yufeng Xie
- State Key Laboratory of ASIC & System, School of Microelectronics, Fudan University, Shanghai 201203, China
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180
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Tereshchenko OE, Golyashov VA, Rusetsky VS, Kustov DA, Mironov AV, Demin AY. Vacuum Spin LED: First Step towards Vacuum Semiconductor Spintronics. Nanomaterials (Basel) 2023; 13:422. [PMID: 36770383 PMCID: PMC9919810 DOI: 10.3390/nano13030422] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 01/06/2023] [Revised: 01/14/2023] [Accepted: 01/17/2023] [Indexed: 06/18/2023]
Abstract
Improving the efficiency of spin generation, injection, and detection remains a key challenge for semiconductor spintronics. Electrical injection and optical orientation are two methods of creating spin polarization in semiconductors, which traditionally require specially tailored p-n junctions, tunnel or Schottky barriers. Alternatively, we introduce here a novel concept for spin-polarized electron emission/injection combining the optocoupler principle based on vacuum spin-polarized light-emitting diode (spin VLED) making it possible to measure the free electron beam polarization injected into the III-V heterostructure with quantum wells (QWs) based on the detection of polarized cathodoluminescence (CL). To study the spin-dependent emission/injection, we developed spin VLEDs, which consist of a compact proximity-focused vacuum tube with a spin-polarized electron source (p-GaAs(Cs,O) or Na2KSb) and the spin detector (III-V heterostructure), both activated to a negative electron affinity (NEA) state. The coupling between the photon helicity and the spin angular momentum of the electrons in the photoemission and injection/detection processes is realized without using either magnetic material or a magnetic field. Spin-current detection efficiency in spin VLED is found to be 27% at room temperature. The created vacuum spin LED paves the way for optical generation and spin manipulation in the developing vacuum semiconductor spintronics.
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Affiliation(s)
- Oleg E. Tereshchenko
- Rzhanov Institute of Semiconductor Physics, Siberian Branch, Russian Academy of Sciences, Novosibirsk 630090, Russia
- Synchrotron Radiation Facility SKIF, Boreskov Institute of Catalysis, Siberian Branch, Russian Academy of Sciences, Kol’tsovo 630559, Russia
| | - Vladimir A. Golyashov
- Rzhanov Institute of Semiconductor Physics, Siberian Branch, Russian Academy of Sciences, Novosibirsk 630090, Russia
- Synchrotron Radiation Facility SKIF, Boreskov Institute of Catalysis, Siberian Branch, Russian Academy of Sciences, Kol’tsovo 630559, Russia
| | - Vadim S. Rusetsky
- Rzhanov Institute of Semiconductor Physics, Siberian Branch, Russian Academy of Sciences, Novosibirsk 630090, Russia
- CJSC “Ekran FEP”, Novosibirsk 630060, Russia
| | - Danil A. Kustov
- Rzhanov Institute of Semiconductor Physics, Siberian Branch, Russian Academy of Sciences, Novosibirsk 630090, Russia
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181
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Andrearczyk T, Levchenko K, Sadowski J, Gas K, Avdonin A, Wróbel J, Figielski T, Sawicki M, Wosinski T. Impact of Bismuth Incorporation into (Ga,Mn)As Dilute Ferromagnetic Semiconductor on Its Magnetic Properties and Magnetoresistance. Materials (Basel) 2023; 16:788. [PMID: 36676524 PMCID: PMC9863846 DOI: 10.3390/ma16020788] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 12/19/2022] [Revised: 01/09/2023] [Accepted: 01/11/2023] [Indexed: 06/17/2023]
Abstract
The impact of bismuth incorporation into the epitaxial layer of a (Ga,Mn)As dilute ferromagnetic semiconductor on its magnetic and electromagnetic properties is studied in very thin layers of quaternary (Ga,Mn)(Bi,As) compound grown on a GaAs substrate under a compressive misfit strain. An addition of a small atomic fraction of 1% Bi atoms, substituting As atoms in the layer, predominantly enhances the spin-orbit coupling strength in its valence band. The presence of bismuth results in a small decrease in the ferromagnetic Curie temperature and a distinct increase in the coercive fields. On the other hand, the Bi incorporation into the layer strongly enhances the magnitude of negative magnetoresistance without affecting the hole concentration in the layer. The negative magnetoresistance is interpreted in terms of the suppression of weak localization in a magnetic field. Application of the weak-localization theory for two-dimensional ferromagnets by Dugaev et al. to the experimental magnetoresistance results indicates that the decrease in spin-orbit scattering length accounts for the enhanced magnetoresistance in (Ga,Mn)(Bi,As).
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Affiliation(s)
- Tomasz Andrearczyk
- Institute of Physics, Polish Academy of Sciences, Aleja Lotnikow 32/46, PL-02668 Warsaw, Poland
| | - Khrystyna Levchenko
- Institute of Physics, Polish Academy of Sciences, Aleja Lotnikow 32/46, PL-02668 Warsaw, Poland
- Faculty of Physics, University of Vienna, 1090 Vienna, Austria
| | - Janusz Sadowski
- Institute of Physics, Polish Academy of Sciences, Aleja Lotnikow 32/46, PL-02668 Warsaw, Poland
- Department of Physics and Electrical Engineering, Linnaeus University, SE-391 82 Kalmar, Sweden
| | - Katarzyna Gas
- Institute of Physics, Polish Academy of Sciences, Aleja Lotnikow 32/46, PL-02668 Warsaw, Poland
| | - Andrei Avdonin
- Institute of Physics, Polish Academy of Sciences, Aleja Lotnikow 32/46, PL-02668 Warsaw, Poland
| | - Jerzy Wróbel
- Institute of Physics, Polish Academy of Sciences, Aleja Lotnikow 32/46, PL-02668 Warsaw, Poland
| | - Tadeusz Figielski
- Institute of Physics, Polish Academy of Sciences, Aleja Lotnikow 32/46, PL-02668 Warsaw, Poland
| | - Maciej Sawicki
- Institute of Physics, Polish Academy of Sciences, Aleja Lotnikow 32/46, PL-02668 Warsaw, Poland
| | - Tadeusz Wosinski
- Institute of Physics, Polish Academy of Sciences, Aleja Lotnikow 32/46, PL-02668 Warsaw, Poland
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182
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Sidorenko AS, Hahn H, Krasnov V. Frontiers of nanoelectronics: intrinsic Josephson effect and prospects of superconducting spintronics. Beilstein J Nanotechnol 2023; 14:79-82. [PMID: 36761675 PMCID: PMC9843234 DOI: 10.3762/bjnano.14.9] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 12/28/2022] [Accepted: 01/03/2023] [Indexed: 06/18/2023]
Affiliation(s)
- Anatolie S Sidorenko
- Institute of Electronic Engineering and Nanotechnologies of the Technical University of Moldova, Academiei 3/3, Chisinau 2028, Moldova
- I.S. Turgenev Orel State University, Komsomolskaya str. 95, 302026, Orel, Russia
| | - Horst Hahn
- Institute of Nanotechnology, Karlsruhe Institute of Technology (KIT), D-76021 Karlsruhe, Germany
- Chemical, Biological and Materials Engineering, The University of Oklahoma, Norman, 73019, OK, United States
| | - Vladimir Krasnov
- Department of Physics, Stockholm University, AlbaNova University Center, SE-10691 Stockholm, Sweden
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183
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Vakhrushev A, Fedotov A, Severyukhina O, Sidorenko A. The influence of structure and local structural defects on the magnetic properties of cobalt nanofilms. Beilstein J Nanotechnol 2023; 14:23-33. [PMID: 36703908 PMCID: PMC9830499 DOI: 10.3762/bjnano.14.3] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 07/21/2022] [Accepted: 12/07/2022] [Indexed: 06/18/2023]
Abstract
The present paper considers a mathematical model describing the time evolution of spin states and magnetic properties of a nanomaterial. We present the results of two variants of nanosystem simulations. In the first variant, cobalt with a structure close to the hexagonal close-packed crystal lattice was considered. In the second case, a cobalt nanofilm formed in the previously obtained numerical experiment of multilayer niobium-cobalt nanocomposite deposition was investigated. The sizes of the systems were the same in both cases. For both simulations, after pre-correction in the initial time stages, the value of spin temperature stabilized and tended to the average value. Also, the change in spin temperature occurred near the average value. The system with a real structure had a variable spin temperature compared to that of a system with an ideal structure. In all cases of calculations for cobalt, the ferromagnetic behavior was preserved. Defects in the structure and local arrangement of the atoms cause a deterioration in the magnetic macroscopic parameters, such as a decrease in the magnetization modulus.
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Affiliation(s)
- Alexander Vakhrushev
- Modeling and Synthesis of Technological Structures Department, Institute of Mechanics, Udmurt Federal Research Centre, Ural Division, Russian Academy of Sciences, Baramzinoy 34, Izhevsk 426067, Russia
- Orel State University named after I.S. Turgenev, Komsomolskaya Str. 95, 302026, Orel, Russia
| | - Aleksey Fedotov
- Modeling and Synthesis of Technological Structures Department, Institute of Mechanics, Udmurt Federal Research Centre, Ural Division, Russian Academy of Sciences, Baramzinoy 34, Izhevsk 426067, Russia
- Orel State University named after I.S. Turgenev, Komsomolskaya Str. 95, 302026, Orel, Russia
- Nanotechnology and Microsystems Department, Kalashnikov Izhevsk State Technical University, Studencheskaya 7, Izhevsk 426069, Russia
| | - Olesya Severyukhina
- Modeling and Synthesis of Technological Structures Department, Institute of Mechanics, Udmurt Federal Research Centre, Ural Division, Russian Academy of Sciences, Baramzinoy 34, Izhevsk 426067, Russia
- Orel State University named after I.S. Turgenev, Komsomolskaya Str. 95, 302026, Orel, Russia
- Nanotechnology and Microsystems Department, Kalashnikov Izhevsk State Technical University, Studencheskaya 7, Izhevsk 426069, Russia
| | - Anatolie Sidorenko
- Orel State University named after I.S. Turgenev, Komsomolskaya Str. 95, 302026, Orel, Russia
- Institute of Electronic Engineering and Nanotechnologies of Technical University of Moldova, Academiei 3/3, Chisinau 2028, Moldova
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184
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Ahrens V, Kiesselbach C, Gnoli L, Giuliano D, Mendisch S, Kiechle M, Riente F, Becherer M. Skyrmions Under Control-FIB Irradiation as a Versatile Tool for Skyrmion Circuits. Adv Mater 2023; 35:e2207321. [PMID: 36255142 DOI: 10.1002/adma.202207321] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 08/11/2022] [Revised: 10/11/2022] [Indexed: 06/16/2023]
Abstract
Magnetic data storage and processing offer certain advances over conventional technologies, amongst which nonvolatility and low power operation are the most outstanding ones. Skyrmions are a promising candidate as a magnetic data carrier. However, the sputtering of skyrmion films and the control of the skyrmion nucleation, motion, and annihilation remains challenging. This work demonstrates that using optimized focused ion beam irradiation and annealing protocols enables the skyrmion phase in W/CoFeB/MgO thin films to be accessed easily. By analyzing ion-beam-engineered skyrmion hosting wires, excited by sub-100 ns current pulses, possibilities to control skyrmion nucleation, guide their motion, and control their annihilation unfold. Overall, the key elements needed to develop extensive skyrmion networks are presented.
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Affiliation(s)
- Valentin Ahrens
- Department of Electrical and Computer Engineering, Technical University of Munich, 85748, Garching, Germany
| | - Clara Kiesselbach
- Department of Electrical and Computer Engineering, Technical University of Munich, 85748, Garching, Germany
| | - Luca Gnoli
- Department of Electronics and Telecommunications, Politecnico di Torino, Torino, 10129, Italy
| | - Domenico Giuliano
- Department of Electronics and Telecommunications, Politecnico di Torino, Torino, 10129, Italy
| | - Simon Mendisch
- Department of Electrical and Computer Engineering, Technical University of Munich, 85748, Garching, Germany
| | - Martina Kiechle
- Department of Electrical and Computer Engineering, Technical University of Munich, 85748, Garching, Germany
| | - Fabrizio Riente
- Department of Electronics and Telecommunications, Politecnico di Torino, Torino, 10129, Italy
| | - Markus Becherer
- Department of Electrical and Computer Engineering, Technical University of Munich, 85748, Garching, Germany
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185
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Chen X, Higo T, Tanaka K, Nomoto T, Tsai H, Idzuchi H, Shiga M, Sakamoto S, Ando R, Kosaki H, Matsuo T, Nishio-Hamane D, Arita R, Miwa S, Nakatsuji S. Octupole-driven magnetoresistance in an antiferromagnetic tunnel junction. Nature 2023; 613:490-495. [PMID: 36653566 PMCID: PMC9849134 DOI: 10.1038/s41586-022-05463-w] [Citation(s) in RCA: 14] [Impact Index Per Article: 14.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/11/2022] [Accepted: 10/19/2022] [Indexed: 01/19/2023]
Abstract
The tunnelling electric current passing through a magnetic tunnel junction (MTJ) is strongly dependent on the relative orientation of magnetizations in ferromagnetic electrodes sandwiching an insulating barrier, rendering efficient readout of spintronics devices1-5. Thus, tunnelling magnetoresistance (TMR) is considered to be proportional to spin polarization at the interface1 and, to date, has been studied primarily in ferromagnets. Here we report observation of TMR in an all-antiferromagnetic tunnel junction consisting of Mn3Sn/MgO/Mn3Sn (ref. 6). We measured a TMR ratio of around 2% at room temperature, which arises between the parallel and antiparallel configurations of the cluster magnetic octupoles in the chiral antiferromagnetic state. Moreover, we carried out measurements using a Fe/MgO/Mn3Sn MTJ and show that the sign and direction of anisotropic longitudinal spin-polarized current in the antiferromagnet7 can be controlled by octupole direction. Strikingly, the TMR ratio (about 2%) of the all-antiferromagnetic MTJ is much larger than that estimated using the observed spin polarization. Theoretically, we found that the chiral antiferromagnetic MTJ may produce a substantially large TMR ratio as a result of the time-reversal, symmetry-breaking polarization characteristic of cluster magnetic octupoles. Our work lays the foundation for the development of ultrafast and efficient spintronic devices using antiferromagnets8-10.
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Affiliation(s)
- Xianzhe Chen
- Department of Physics, University of Tokyo, Tokyo, Japan.,Institute for Solid State Physics, University of Tokyo, Chiba, Japan
| | - Tomoya Higo
- Department of Physics, University of Tokyo, Tokyo, Japan.,Institute for Solid State Physics, University of Tokyo, Chiba, Japan.,CREST, Japan Science and Technology Agency, Saitama, Japan
| | - Katsuhiro Tanaka
- Research Center for Advanced Science and Technology, University of Tokyo, Tokyo, Japan
| | - Takuya Nomoto
- Research Center for Advanced Science and Technology, University of Tokyo, Tokyo, Japan.,PRESTO, Japan Science and Technology Agency, Saitama, Japan
| | - Hanshen Tsai
- Department of Physics, University of Tokyo, Tokyo, Japan.,Institute for Solid State Physics, University of Tokyo, Chiba, Japan
| | - Hiroshi Idzuchi
- Department of Physics, University of Tokyo, Tokyo, Japan.,Institute for Solid State Physics, University of Tokyo, Chiba, Japan
| | - Masanobu Shiga
- Institute for Solid State Physics, University of Tokyo, Chiba, Japan
| | - Shoya Sakamoto
- Institute for Solid State Physics, University of Tokyo, Chiba, Japan
| | - Ryoya Ando
- Institute for Solid State Physics, University of Tokyo, Chiba, Japan
| | - Hidetoshi Kosaki
- Institute for Solid State Physics, University of Tokyo, Chiba, Japan
| | - Takumi Matsuo
- Department of Physics, University of Tokyo, Tokyo, Japan
| | | | - Ryotaro Arita
- CREST, Japan Science and Technology Agency, Saitama, Japan.,Research Center for Advanced Science and Technology, University of Tokyo, Tokyo, Japan.,RIKEN, Center for Emergent Matter Science, Saitama, Japan
| | - Shinji Miwa
- Institute for Solid State Physics, University of Tokyo, Chiba, Japan.,CREST, Japan Science and Technology Agency, Saitama, Japan.,Trans-scale Quantum Science Institute, University of Tokyo, Tokyo, Japan
| | - Satoru Nakatsuji
- Department of Physics, University of Tokyo, Tokyo, Japan. .,Institute for Solid State Physics, University of Tokyo, Chiba, Japan. .,CREST, Japan Science and Technology Agency, Saitama, Japan. .,Trans-scale Quantum Science Institute, University of Tokyo, Tokyo, Japan. .,Canadian Institute for Advanced Research, Toronto, Ontario, Canada.
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186
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Vakili H, Ganguly S, de Coster GJ, Neupane MR, Ghosh AW. Low Power In-Memory Computation with Reciprocal Ferromagnet/Topological Insulator Heterostructures. ACS Nano 2022; 16:20222-20228. [PMID: 36459145 PMCID: PMC9798907 DOI: 10.1021/acsnano.2c05645] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 06/08/2022] [Accepted: 11/29/2022] [Indexed: 06/17/2023]
Abstract
The surface state of a 3D topological insulator (3DTI) is a spin-momentum locked conductive state, whose large spin hall angle can be used for the energy-efficient spin-orbit torque based switching of an overlying ferromagnet (FM). Conversely, the gated switching of the magnetization of a separate FM in or out of the TI surface plane can turn on and off the TI surface current. By exploiting this reciprocal behavior, we can use two FM/3DTI heterostructures to design an integrated 1-transistor 1-magnetic tunnel junction random access memory unit (1T1MTJ RAM) for an ultra low power Processing-in-Memory (PiM) architecture. Our calculation involves combining the Fokker-Planck equation with the Nonequilibrium Green Function (NEGF) based flow of conduction electrons and Landau-Lifshitz-Gilbert (LLG) based dynamics of magnetization. Our combined approach allows us to connect device performance metrics with underlying material parameters, which can guide proposed experimental and fabrication efforts.
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Affiliation(s)
- Hamed Vakili
- Department
of Physics, University of Virginia, Charlottesville, Virginia22904, United States
| | - Samiran Ganguly
- Department
of Electrical and Computer Engineering, University of Virginia, Charlottesville, Virginia22904, United States
- Department
of Electrical and Computer Engineering, Virginia Commonwealth University, Richmond, Virginia23284, United States
| | - George J. de Coster
- DEVCOM
Army Research Laboratory, 2800 Powder Mill Road, Adelphi, Maryland20783, United
States
| | - Mahesh R. Neupane
- DEVCOM
Army Research Laboratory, 2800 Powder Mill Road, Adelphi, Maryland20783, United
States
- Materials
Science and Engineering Program, University
of California, Riverside, California92521, United States
| | - Avik W. Ghosh
- Department
of Physics, University of Virginia, Charlottesville, Virginia22904, United States
- Department
of Electrical and Computer Engineering, University of Virginia, Charlottesville, Virginia22904, United States
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187
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Priyanka P, Makani NH, Banerjee R, Sarkar I. Heavy metal deposition temperature tuned spin pumping efficiency control in permalloy/tantalum bilayers. Nanotechnology 2022; 34:105705. [PMID: 36562510 DOI: 10.1088/1361-6528/aca983] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 09/13/2022] [Accepted: 12/07/2022] [Indexed: 06/17/2023]
Abstract
Spin pumping is a key property for spintronic application that can be realized in heavy metal/ferromagnet bilayers. Here we demonstrate the possibility of improving spin pumping in permalloy (Py)/tantalum (Ta) bilayers through control of Ta heavy metal deposition temperature. Through a combination of structural and ferromagnetic resonance based magnetization dynamics study, we reveal the role of Ta deposition temperature in improving spin mixing conductance which is a key parameter for spin pumping across the Py/Ta interface. The results show that by depositing Ta above room temperature, a high spin mixing conductance of 7.7 ×1018m-2is obtained withα-Ta layer. The results present an understanding of the correlation between heavy metal deposition temperature and interface structure improvement and consequent control of spin pumping in Py/Ta bilayers.
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Affiliation(s)
- P Priyanka
- Institute of Nano Science and Technology, Sector 81, Sahibzada Ajit Singh Nagar, Punjab 140306, India
| | - N H Makani
- Department of Physics, Indian Institute of Technology Gandhinagar, Palaj 382355, India
| | - R Banerjee
- Department of Physics, Indian Institute of Technology Gandhinagar, Palaj 382355, India
| | - I Sarkar
- Institute of Nano Science and Technology, Sector 81, Sahibzada Ajit Singh Nagar, Punjab 140306, India
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188
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Guanghui Cheng, Mohammad Mushfiqur Rahman, Zhiping He, Andres Llacsahuanga Allcca, Avinash Rustagi, Kirstine Aggerbeck Stampe, Yanglin Zhu, Shaohua Yan, Shangjie Tian, Zhiqiang Mao, Hechang Lei, Kenji Watanabe, Takashi Taniguchi, Pramey Upadhyaya, Yong P. Chen. Emergence of electric-field-tunable interfacial ferromagnetism in 2D antiferromagnet heterostructures. Nat Commun 2022; 13:7348. [PMID: 36522317 DOI: 10.1038/s41467-022-34812-6] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/09/2022] [Accepted: 11/08/2022] [Indexed: 12/23/2022] Open
Abstract
Van der Waals (vdW) magnet heterostructures have emerged as new platforms to explore exotic magnetic orders and quantum phenomena. Here, we study heterostructures of layered antiferromagnets, CrI3 and CrCl3, with perpendicular and in-plane magnetic anisotropy, respectively. Using magneto-optical Kerr effect microscopy, we demonstrate out-of-plane magnetic order in the CrCl3 layer proximal to CrI3, with ferromagnetic interfacial coupling between the two. Such an interlayer exchange field leads to higher critical temperature than that of either CrI3 or CrCl3 alone. We further demonstrate significant electric-field control of the coercivity, attributed to the naturally broken structural inversion symmetry of the heterostructure allowing unprecedented direct coupling between electric field and interfacial magnetism. These findings illustrate the opportunity to explore exotic magnetic phases and engineer spintronic devices in vdW heterostructures.
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189
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Imai Y, Nakajima K, Tsunegi S, Taniguchi T. Input-driven chaotic dynamics in vortex spin-torque oscillator. Sci Rep 2022; 12:21651. [PMID: 36522401 PMCID: PMC9755258 DOI: 10.1038/s41598-022-26018-z] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/28/2022] [Accepted: 12/08/2022] [Indexed: 12/23/2022] Open
Abstract
A new research topic in spintronics relating to the operation principles of brain-inspired computing is input-driven magnetization dynamics in nanomagnet. In this paper, the magnetization dynamics in a vortex spin-torque oscillator driven by a series of random magnetic field are studied through a numerical simulation of the Thiele equation. It is found that input-driven synchronization occurs in the weak perturbation limit, as found recently. As well, chaotic behavior is newly found to occur in the vortex core dynamics for a wide range of parameters, where synchronized behavior is disrupted by an intermittency. Ordered and chaotic dynamical phases are examined by evaluating the Lyapunov exponent. The relation between the dynamical phase and the computational capability of physical reservoir computing is also studied.
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Affiliation(s)
- Yusuke Imai
- grid.208504.b0000 0001 2230 7538Research Center for Emerging Computing Technologies, National Institute of Advanced Industrial Science and Technology (AIST), Tsukuba, Ibaraki 305-8568 Japan
| | - Kohei Nakajima
- grid.26999.3d0000 0001 2151 536XGraduate School of Information Science and Technology, The University of Tokyo, Bunkyo-ku, Tokyo, 113-8656 Japan
| | - Sumito Tsunegi
- grid.208504.b0000 0001 2230 7538Research Center for Emerging Computing Technologies, National Institute of Advanced Industrial Science and Technology (AIST), Tsukuba, Ibaraki 305-8568 Japan ,grid.419082.60000 0004 1754 9200Japan Science and Technology Agency (JST), PRESTO, Saitama, 332-0012 Japan
| | - Tomohiro Taniguchi
- grid.208504.b0000 0001 2230 7538Research Center for Emerging Computing Technologies, National Institute of Advanced Industrial Science and Technology (AIST), Tsukuba, Ibaraki 305-8568 Japan
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190
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One RA, Mican S, CimpoesȖu AG, Joldos M, Tetean R, Tiușan CV. Micromagnetic Design of Skyrmionic Materials and Chiral Magnetic Configurations in Patterned Nanostructures for Neuromorphic and Qubit Applications. Nanomaterials (Basel) 2022; 12:4411. [PMID: 36558263 PMCID: PMC9782460 DOI: 10.3390/nano12244411] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 11/14/2022] [Revised: 12/02/2022] [Accepted: 12/06/2022] [Indexed: 06/17/2023]
Abstract
Our study addresses the problematics of magnetic skyrmions, nanometer-size vortex-like swirling topological defects, broadly studied today for applications in classic, neuromorphic and quantum information technologies. We tackle some challenging issues of material properties versus skyrmion stability and manipulation within a multiple-scale modeling framework, involving complementary ab-initio and micromagnetic frameworks. Ab-initio calculations provide insight into the anatomy of the magnetic anisotropy, the Dzyaloshinskii-Moriya asymmetric exchange interaction (DMI) and their response to a gating electric field. Various multi-layered heterostructures were specially designed to provide electric field tunable perpendicular magnetization and sizeable DMI, which are required for skyrmion occurrence. Landau-Lifshitz-Gilbert micromagnetic calculations in nanometric disks allowed the extraction of material parameter phase diagrams in which magnetic textures were classified according to their topological charge. We identified suitable ranges of magnetic anisotropy, DMI and saturation magnetization for stabilizing skyrmionic ground states or writing/manipulating them using either a spin-transfer torque of a perpendicular current or the electric field. From analyzing the different contributions to the total magnetic free energy, we point out some critical properties influencing the skyrmions' stability. Finally, we discuss some experimental issues related to the choice of materials or the design of novel magnetic materials compatible with skyrmionic applications.
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Affiliation(s)
- Roxana-Alina One
- Department of Condensed Matter Physics and Advanced Technologies, Faculty of Physics, Babeș-Bolyai University of Cluj-Napoca, 400084 Cluj-Napoca, Romania
| | - Sever Mican
- Department of Condensed Matter Physics and Advanced Technologies, Faculty of Physics, Babeș-Bolyai University of Cluj-Napoca, 400084 Cluj-Napoca, Romania
| | - Angela-Georgiana CimpoesȖu
- Department of Condensed Matter Physics and Advanced Technologies, Faculty of Physics, Babeș-Bolyai University of Cluj-Napoca, 400084 Cluj-Napoca, Romania
| | - Marius Joldos
- Computer Science Department, Faculty of Automation and Computer Science, Technical University of Cluj-Napoca, 400027 Cluj-Napoca, Romania
| | - Romulus Tetean
- Department of Condensed Matter Physics and Advanced Technologies, Faculty of Physics, Babeș-Bolyai University of Cluj-Napoca, 400084 Cluj-Napoca, Romania
| | - Coriolan Viorel Tiușan
- Department of Condensed Matter Physics and Advanced Technologies, Faculty of Physics, Babeș-Bolyai University of Cluj-Napoca, 400084 Cluj-Napoca, Romania
- National Center of Scientific Research, 54500 Vandoeuvre-lès-Nancy, France
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191
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Fiorentini S, Bendra M, Ender J, de Orio RL, Goes W, Selberherr S, Sverdlov V. Spin and charge drift-diffusion in ultra-scaled MRAM cells. Sci Rep 2022; 12:20958. [PMID: 36471161 PMCID: PMC9723118 DOI: 10.1038/s41598-022-25586-4] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/31/2022] [Accepted: 12/01/2022] [Indexed: 12/12/2022] Open
Abstract
Designing advanced single-digit shape-anisotropy MRAM cells requires an accurate evaluation of spin currents and torques in magnetic tunnel junctions (MTJs) with elongated free and reference layers. For this purpose, we extended the analysis approach successfully used in nanoscale metallic spin valves to MTJs by introducing proper boundary conditions for the spin currents at the tunnel barrier interfaces, and by employing a conductivity locally dependent on the angle between the magnetization vectors for the charge current. The experimentally measured voltage and angle dependencies of the torques acting on the free layer are thereby accurately reproduced. The switching behavior of ultra-scaled MRAM cells is in agreement with recent experiments on shape-anisotropy MTJs. Using our extended approach is absolutely essential to accurately capture the interplay of the Slonczewski and Zhang-Li torque contributions acting on a textured magnetization in composite free layers with the inclusion of several MgO barriers.
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Affiliation(s)
- Simone Fiorentini
- Christian Doppler Laboratory for Nonvolatile Magnetoresistive Memory and Logic, Vienna, Austria ,grid.5329.d0000 0001 2348 4034Institute for Microelectronics, TU Wien, Gußhausstraße 27–29/E360, 1040 Vienna, Austria
| | - Mario Bendra
- Christian Doppler Laboratory for Nonvolatile Magnetoresistive Memory and Logic, Vienna, Austria ,grid.5329.d0000 0001 2348 4034Institute for Microelectronics, TU Wien, Gußhausstraße 27–29/E360, 1040 Vienna, Austria
| | - Johannes Ender
- Christian Doppler Laboratory for Nonvolatile Magnetoresistive Memory and Logic, Vienna, Austria ,grid.5329.d0000 0001 2348 4034Institute for Microelectronics, TU Wien, Gußhausstraße 27–29/E360, 1040 Vienna, Austria
| | - Roberto L. de Orio
- Christian Doppler Laboratory for Nonvolatile Magnetoresistive Memory and Logic, Vienna, Austria ,grid.5329.d0000 0001 2348 4034Institute for Microelectronics, TU Wien, Gußhausstraße 27–29/E360, 1040 Vienna, Austria
| | | | - Siegfried Selberherr
- grid.5329.d0000 0001 2348 4034Institute for Microelectronics, TU Wien, Gußhausstraße 27–29/E360, 1040 Vienna, Austria
| | - Viktor Sverdlov
- Christian Doppler Laboratory for Nonvolatile Magnetoresistive Memory and Logic, Vienna, Austria ,grid.5329.d0000 0001 2348 4034Institute for Microelectronics, TU Wien, Gußhausstraße 27–29/E360, 1040 Vienna, Austria
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192
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Wang Q, Lu Y, He RL, Chen R, Qiao L, Pan F, Yang Z, Song C. Spin Selectivity in Chiral Hybrid Cobalt Halide Films with Ultrasmooth Surface. Small Methods 2022; 6:e2201048. [PMID: 36403249 DOI: 10.1002/smtd.202201048] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 08/26/2022] [Revised: 10/25/2022] [Indexed: 06/16/2023]
Abstract
Introducing chirality into low-dimensional hybrid organic-inorganic halides (HOIHs) creates brand-new opportunities for HOIHs in spintronics and spin-related optoelectronics owing to chirality-induced spin selectivity (CISS). However, preparing smooth films of low-dimensional HOIHs with small roughness is still a great challenge due to the hybrid and complex crystal structure, which severely inhibits their applications in spintronic devices. Exploring new lead-free chiral HOIHs with both efficient spin selectivity and excellent film quality is urgently desired. Here, cobalt-based chiral metal halide crystals (R/S-NEA)2 CoCl4 constructed by 0D [CoCl4 ] tetrahedrons and 1-(1-naphtyl)ethylamine (NEA) are synthesized. The orderly configuration of NEA molecules stabilized by noncovalent CH···π interaction endows (NEA)2 CoCl4 with good film-forming ability. (NEA)2 CoCl4 films exhibit strong chiroptical activity (gCD ≈ 0.05) and significant spin-polarized transport (CISS efficiency up to 90%). Furthermore, ultrasmooth films (roughness ∼ 0.3 nm) with enhanced crystallinity can be achieved by incorporating tiny amount tris(8-oxoquinoline)aluminum that has analogous conjugated structure to NEA. The realization of highly efficient spin selectivity and sub-nanometer roughness in lead-free chiral halides can boost the practical process of low-dimensional HOIHs in spintronics and other fields.
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Affiliation(s)
- Qian Wang
- Key Laboratory of Advanced Materials (MOE), School of Materials Science and Engineering, Tsinghua University, Beijing, 100084, China
| | - Ying Lu
- Department of Materials Physics and Chemistry, School of Materials Science and Engineering, University of Science and Technology Beijing, Beijing, 100083, China
| | - Rui-Lin He
- Department of Chemistry, Key Laboratory of Organic Optoelectronics and Molecular Engineering of the Ministry of Education, Tsinghua University Beijing, Beijing, 100084, China
| | - Ruyi Chen
- Key Laboratory of Advanced Materials (MOE), School of Materials Science and Engineering, Tsinghua University, Beijing, 100084, China
| | - Leilei Qiao
- Key Laboratory of Advanced Materials (MOE), School of Materials Science and Engineering, Tsinghua University, Beijing, 100084, China
| | - Feng Pan
- Key Laboratory of Advanced Materials (MOE), School of Materials Science and Engineering, Tsinghua University, Beijing, 100084, China
| | - Zhou Yang
- Department of Materials Physics and Chemistry, School of Materials Science and Engineering, University of Science and Technology Beijing, Beijing, 100083, China
| | - Cheng Song
- Key Laboratory of Advanced Materials (MOE), School of Materials Science and Engineering, Tsinghua University, Beijing, 100084, China
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193
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Chowrira B, Kandpal L, Lamblin M, Ngassam F, Kouakou CA, Zafar T, Mertz D, Vileno B, Kieber C, Versini G, Gobaut B, Joly L, Ferté T, Monteblanco E, Bahouka A, Bernard R, Mohapatra S, Prima Garcia H, Elidrissi S, Gavara M, Sternitzky E, Da Costa V, Hehn M, Montaigne F, Choueikani F, Ohresser P, Lacour D, Weber W, Boukari S, Alouani M, Bowen M. Quantum Advantage in a Molecular Spintronic Engine that Harvests Thermal Fluctuation Energy. Adv Mater 2022; 34:e2206688. [PMID: 36177716 DOI: 10.1002/adma.202206688] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/22/2022] [Revised: 09/25/2022] [Indexed: 06/16/2023]
Abstract
Recent theory and experiments have showcased how to harness quantum mechanics to assemble heat/information engines with efficiencies that surpass the classical Carnot limit. So far, this has required atomic engines that are driven by cumbersome external electromagnetic sources. Here, using molecular spintronics, an implementation that is both electronic and autonomous is proposed. The spintronic quantum engine heuristically deploys several known quantum assets by having a chain of spin qubits formed by the paramagnetic Co center of phthalocyanine (Pc) molecules electronically interact with electron-spin-selecting Fe/C60 interfaces. Density functional calculations reveal that transport fluctuations across the interface can stabilize spin coherence on the Co paramagnetic centers, which host spin flip processes. Across vertical molecular nanodevices, enduring dc current generation, output power above room temperature, two quantum thermodynamical signatures of the engine's processes, and a record 89% spin polarization of current across the Fe/C60 interface are measured. It is crucially this electron spin selection that forces, through demonic feedback and control, charge current to flow against the built-in potential barrier. Further research into spintronic quantum engines, insight into the quantum information processes within spintronic technologies, and retooling the spintronic-based information technology chain, can help accelerate the transition to clean energy.
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Affiliation(s)
- Bhavishya Chowrira
- Institut de Physique et Chimie des Matériaux de Strasbourg, UMR 7504 CNRS, Université de Strasbourg, 23 Rue du Lœss, BP 43, Strasbourg, 67034, France
- Synchrotron SOLEIL, L'Orme des Merisiers, Saint-Aubin, BP 48, Gif-sur-Yvette, 91192, France
| | - Lalit Kandpal
- Institut de Physique et Chimie des Matériaux de Strasbourg, UMR 7504 CNRS, Université de Strasbourg, 23 Rue du Lœss, BP 43, Strasbourg, 67034, France
| | - Mathieu Lamblin
- Institut de Physique et Chimie des Matériaux de Strasbourg, UMR 7504 CNRS, Université de Strasbourg, 23 Rue du Lœss, BP 43, Strasbourg, 67034, France
| | - Franck Ngassam
- Institut de Physique et Chimie des Matériaux de Strasbourg, UMR 7504 CNRS, Université de Strasbourg, 23 Rue du Lœss, BP 43, Strasbourg, 67034, France
| | - Charles-Ambroise Kouakou
- Institut de Physique et Chimie des Matériaux de Strasbourg, UMR 7504 CNRS, Université de Strasbourg, 23 Rue du Lœss, BP 43, Strasbourg, 67034, France
| | - Talha Zafar
- Institut de Physique et Chimie des Matériaux de Strasbourg, UMR 7504 CNRS, Université de Strasbourg, 23 Rue du Lœss, BP 43, Strasbourg, 67034, France
| | - Damien Mertz
- Institut de Physique et Chimie des Matériaux de Strasbourg, UMR 7504 CNRS, Université de Strasbourg, 23 Rue du Lœss, BP 43, Strasbourg, 67034, France
| | - Bertrand Vileno
- Institut de Chimie, UMR 7177 CNRS, Université de Strasbourg, 4 Rue Blaise Pascal, CS 90032, Strasbourg, 67081, France
| | - Christophe Kieber
- Institut de Physique et Chimie des Matériaux de Strasbourg, UMR 7504 CNRS, Université de Strasbourg, 23 Rue du Lœss, BP 43, Strasbourg, 67034, France
| | - Gilles Versini
- Institut de Physique et Chimie des Matériaux de Strasbourg, UMR 7504 CNRS, Université de Strasbourg, 23 Rue du Lœss, BP 43, Strasbourg, 67034, France
| | - Benoit Gobaut
- Institut de Physique et Chimie des Matériaux de Strasbourg, UMR 7504 CNRS, Université de Strasbourg, 23 Rue du Lœss, BP 43, Strasbourg, 67034, France
| | - Loïc Joly
- Institut de Physique et Chimie des Matériaux de Strasbourg, UMR 7504 CNRS, Université de Strasbourg, 23 Rue du Lœss, BP 43, Strasbourg, 67034, France
| | - Tom Ferté
- Institut de Physique et Chimie des Matériaux de Strasbourg, UMR 7504 CNRS, Université de Strasbourg, 23 Rue du Lœss, BP 43, Strasbourg, 67034, France
| | - Elmer Monteblanco
- Institut Jean Lamour UMR 7198 CNRS, Université de Lorraine, BP 70239, Vandœuvre les Nancy, 54506, France
| | - Armel Bahouka
- IREPA LASER, Institut Carnot MICA, Parc d'innovation - Pole API, Illkirch, 67400, France
| | - Romain Bernard
- Institut de Physique et Chimie des Matériaux de Strasbourg, UMR 7504 CNRS, Université de Strasbourg, 23 Rue du Lœss, BP 43, Strasbourg, 67034, France
| | - Sambit Mohapatra
- Institut de Physique et Chimie des Matériaux de Strasbourg, UMR 7504 CNRS, Université de Strasbourg, 23 Rue du Lœss, BP 43, Strasbourg, 67034, France
| | - Helena Prima Garcia
- Instituto de Ciencia Molecular (ICMol), Universidad de Valencia, Catedrático Jose Beltrán 2, Paterna, 46980, Spain
| | - Safaa Elidrissi
- Instituto de Ciencia Molecular (ICMol), Universidad de Valencia, Catedrático Jose Beltrán 2, Paterna, 46980, Spain
| | - Miguel Gavara
- Instituto de Ciencia Molecular (ICMol), Universidad de Valencia, Catedrático Jose Beltrán 2, Paterna, 46980, Spain
| | - Emmanuel Sternitzky
- Institut de Physique et Chimie des Matériaux de Strasbourg, UMR 7504 CNRS, Université de Strasbourg, 23 Rue du Lœss, BP 43, Strasbourg, 67034, France
| | - Victor Da Costa
- Institut de Physique et Chimie des Matériaux de Strasbourg, UMR 7504 CNRS, Université de Strasbourg, 23 Rue du Lœss, BP 43, Strasbourg, 67034, France
| | - Michel Hehn
- Institut Jean Lamour UMR 7198 CNRS, Université de Lorraine, BP 70239, Vandœuvre les Nancy, 54506, France
| | - François Montaigne
- Institut Jean Lamour UMR 7198 CNRS, Université de Lorraine, BP 70239, Vandœuvre les Nancy, 54506, France
| | - Fadi Choueikani
- Synchrotron SOLEIL, L'Orme des Merisiers, Saint-Aubin, BP 48, Gif-sur-Yvette, 91192, France
| | - Philippe Ohresser
- Synchrotron SOLEIL, L'Orme des Merisiers, Saint-Aubin, BP 48, Gif-sur-Yvette, 91192, France
| | - Daniel Lacour
- Institut Jean Lamour UMR 7198 CNRS, Université de Lorraine, BP 70239, Vandœuvre les Nancy, 54506, France
| | - Wolfgang Weber
- Institut de Physique et Chimie des Matériaux de Strasbourg, UMR 7504 CNRS, Université de Strasbourg, 23 Rue du Lœss, BP 43, Strasbourg, 67034, France
| | - Samy Boukari
- Institut de Physique et Chimie des Matériaux de Strasbourg, UMR 7504 CNRS, Université de Strasbourg, 23 Rue du Lœss, BP 43, Strasbourg, 67034, France
| | - Mebarek Alouani
- Institut de Physique et Chimie des Matériaux de Strasbourg, UMR 7504 CNRS, Université de Strasbourg, 23 Rue du Lœss, BP 43, Strasbourg, 67034, France
| | - Martin Bowen
- Institut de Physique et Chimie des Matériaux de Strasbourg, UMR 7504 CNRS, Université de Strasbourg, 23 Rue du Lœss, BP 43, Strasbourg, 67034, France
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194
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Rychły-Gruszecka J, Walowski J, Denker C, Tubandt T, Münzenberg M, Kłos JW. Shaping the spin wave spectra of planar 1D magnonic crystals by the geometrical constraints. Sci Rep 2022; 12:20678. [PMID: 36450794 DOI: 10.1038/s41598-022-24969-x] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/18/2022] [Accepted: 11/22/2022] [Indexed: 12/03/2022] Open
Abstract
We present experimental and numerical studies demonstrating the influence of geometrical parameters on the fundamental spin-wave mode in planar 1D magnonic crystals. The investigated magnonic crystals consist of flat stripes separated by air gaps. The adjustment of geometrical parameters allows tailoring of the spin-wave frequencies. The width of stripes and the width of gaps between them affect spin-wave frequencies in two ways. First, directly by geometrical constraints confining the spin waves inside the stripes. Second, indirectly by spin-wave pinning, freeing the spin waves to a different extent on the edges of stripes. Experimentally, the fundamental spin-wave mode frequencies are measured using an all-optical pump-probe time-resolved magneto-optical Kerr-effect setup. Our studies address the problem of spin-wave confinement and spin-wave dipolar pinning in an array of coupled stripes. We show that the frequency of fundamental mode can be tuned to a large extent by adjusting the width of the stripes and the width of gaps between them.
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195
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Dahal BR, Grizzle A, D'Angelo C, Lamberti V, Tyagi P. Competing Easy-Axis Anisotropies Impacting Magnetic Tunnel Junction-Based Molecular Spintronics Devices (MTJMSDs). Int J Mol Sci 2022; 23. [PMID: 36430956 DOI: 10.3390/ijms232214476] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/03/2022] [Revised: 11/16/2022] [Accepted: 11/16/2022] [Indexed: 11/23/2022] Open
Abstract
Molecular spintronics devices (MSDs) attempt to harness molecules' quantum state, size, and configurable attributes for application in computer devices-a quest that began more than 70 years ago. In the vast number of theoretical studies and limited experimental attempts, MSDs have been found to be suitable for application in memory devices and futuristic quantum computers. MSDs have recently also exhibited intriguing spin photovoltaic-like phenomena, signaling their potential application in cost-effective and novel solar cell technologies. The molecular spintronics field's major challenge is the lack of mass-fabrication methods producing robust magnetic molecule connections with magnetic electrodes of different anisotropies. Another main challenge is the limitations of conventional theoretical methods for understanding experimental results and designing new devices. Magnetic tunnel junction-based molecular spintronics devices (MTJMSDs) are designed by covalently connecting paramagnetic molecules across an insulating tunneling barrier. The insulating tunneling barrier serves as a mechanical spacer between two ferromagnetic (FM) electrodes of tailorable magnetic anisotropies to allow molecules to undergo many intriguing phenomena. Our experimental studies showed that the paramagnetic molecules could produce strong antiferromagnetic coupling between two FM electrodes, leading to a dramatic large-scale impact on the magnetic electrode itself. Recently, we showed that the Monte Carlo Simulation (MCS) was effective in providing plausible insights into the observation of unusual magnetic domains based on the role of single easy-axis magnetic anisotropy. Here, we experimentally show that the response of a paramagnetic molecule is dramatically different when connected to FM electrodes of different easy-axis anisotropies. Motivated by our experimental studies, here, we report on an MCS study investigating the impact of the simultaneous presence of two easy-axis anisotropies on MTJMSD equilibrium properties. In-plane easy-axis anisotropy produced multiple magnetic phases of opposite spins. The multiple magnetic phases vanished at higher thermal energy, but the MTJMSD still maintained a higher magnetic moment because of anisotropy. The out-of-plane easy-axis anisotropy caused a dominant magnetic phase in the FM electrode rather than multiple magnetic phases. The simultaneous application of equal-magnitude in-plane and out-of-plane easy-axis anisotropies on the same electrode negated the anisotropy effect. Our experimental and MCS study provides insights for designing and understanding new spintronics-based devices.
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196
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Lopes V, Chiappe G, Ribeiro LC, Anda EV. Totally Spin-Polarized Currents in an Interferometer with Spin-Orbit Coupling and the Absence of Magnetic Field Effects. Nanomaterials (Basel) 2022; 12:4082. [PMID: 36432367 PMCID: PMC9696532 DOI: 10.3390/nano12224082] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 10/26/2022] [Revised: 11/14/2022] [Accepted: 11/16/2022] [Indexed: 06/16/2023]
Abstract
The paper studies the electronic current in a one-dimensional lead under the effect of spin-orbit coupling and its injection into a metallic conductor through two contacts, forming a closed loop. When an external potential is applied, the time reversal symmetry is broken and the wave vector k of the circulating electrons that contribute to the current is spin-dependent. As the wave function phase depends upon the vector k, the closed path in the circuit produces spin-dependent current interference. This creates a physical scenario in which a spin-polarized current emerges, even in the absence of external magnetic fields or magnetic materials. It is possible to find points in the system's parameter space and, depending upon its geometry, the value of the Fermi energy and the spin-orbit intensities, for which the electronic states participating in the current have only one spin, creating a high and totally spin-polarized conductance. For a potential of a few tens of meV, it is possible to obtain a spin-polarized current of the order of μA. The properties of the obtained electronic current qualify the proposed device as a potentially important tool for spintronics applications.
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Affiliation(s)
- Victor Lopes
- Departamento de Física Aplicada, Universidad de Alicante, San Vicente del Raspeig, 03690 Alicante, Spain
| | - Guillermo Chiappe
- Departamento de Física Aplicada, Universidad de Alicante, San Vicente del Raspeig, 03690 Alicante, Spain
| | - Laercio C. Ribeiro
- Centro Federal de Educação Tecnológica Celso Suckow da Fonseca CEFET/RJ, Campus Nova Iguaçu, Nova Iguaçu, Rio de Janeiro 26041-271, Brazil
| | - Enrique V. Anda
- Departamento de Física, Pontifícia Universidade Católica do Rio de Janeiro (PUC-Rio), Rio de Janeiro 22451-900, Brazil
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197
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Yang S, Ju TS, Kim C, Kim HJ, An K, Moon KW, Park S, Hwang C. Magnetic Field Magnitudes Needed for Skyrmion Generation in a General Perpendicularly Magnetized Film. Nano Lett 2022; 22:8430-8436. [PMID: 36282733 PMCID: PMC9650724 DOI: 10.1021/acs.nanolett.2c02268] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 06/06/2022] [Revised: 10/08/2022] [Indexed: 06/16/2023]
Abstract
Due to its topological protection, the magnetic skyrmion has been intensively studied for both fundamental aspects and spintronics applications. However, despite recent advancements in skyrmion research, the deterministic creation of isolated skyrmions in a generic perpendicularly magnetized film is still one of the most essential and challenging techniques. Here, we present a method to create magnetic skyrmions in typical perpendicular magnetic anisotropy (PMA) films by applying a magnetic field pulse and a method to determine the magnitude of the required external magnetic fields. Furthermore, to demonstrate the usefulness of this result for future skyrmion research, we also experimentally study the PMA dependence on the minimum size of skyrmions. Although field-driven skyrmion generation is unsuitable for device application, this result can provide an easier approach for obtaining isolated skyrmions, making skyrmion-based research more accessible.
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Affiliation(s)
- Seungmo Yang
- Quantum
Spin Team, Korea Research Institute of Standards
and Science, Daejeon34113, Republic of Korea
| | - Tae-Seong Ju
- Quantum
Spin Team, Korea Research Institute of Standards
and Science, Daejeon34113, Republic of Korea
- Department
of Physics, Pusan National University, Busan46241, Republic of Korea
| | - Changsoo Kim
- Quantum
Spin Team, Korea Research Institute of Standards
and Science, Daejeon34113, Republic of Korea
| | - Hyun-Joong Kim
- Quantum
Spin Team, Korea Research Institute of Standards
and Science, Daejeon34113, Republic of Korea
| | - Kyongmo An
- Quantum
Spin Team, Korea Research Institute of Standards
and Science, Daejeon34113, Republic of Korea
| | - Kyoung-Woong Moon
- Quantum
Spin Team, Korea Research Institute of Standards
and Science, Daejeon34113, Republic of Korea
| | - Sungkyun Park
- Department
of Physics, Pusan National University, Busan46241, Republic of Korea
| | - Chanyong Hwang
- Quantum
Spin Team, Korea Research Institute of Standards
and Science, Daejeon34113, Republic of Korea
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198
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Ohara K, Zhang X, Chen Y, Kato S, Xia J, Ezawa M, Tretiakov OA, Hou Z, Zhou Y, Zhao G, Yang J, Liu X. Reversible Transformation between Isolated Skyrmions and Bimerons. Nano Lett 2022; 22:8559-8566. [PMID: 36259745 DOI: 10.1021/acs.nanolett.2c03106] [Citation(s) in RCA: 6] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/16/2023]
Abstract
Skyrmions and bimerons are versatile topological spin textures that can be used as information bits for both classical and quantum computing. The transformation between isolated skyrmions and bimerons is an essential operation for computing architecture based on multiple different topological bits. Here we report the creation of isolated skyrmions and their subsequent transformation to bimerons by harnessing the electric current-induced Oersted field and temperature-induced perpendicular magnetic anisotropy variation. The transformation between skyrmions and bimerons is reversible, which is controlled by the current amplitude and scanning direction. Both skyrmions and bimerons can be created in the same system through the skyrmion-bimeron transformation and magnetization switching. Deformed skyrmion bubbles and chiral labyrinth domains are found as nontrivial intermediate transition states. Our results may provide a unique way for building advanced information-processing devices using different types of topological spin textures in the same system.
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Affiliation(s)
- Kentaro Ohara
- Department of Electrical and Computer Engineering, Shinshu University, 4-17-1 Wakasato, Nagano380-8553, Japan
| | - Xichao Zhang
- Department of Electrical and Computer Engineering, Shinshu University, 4-17-1 Wakasato, Nagano380-8553, Japan
| | - Yinling Chen
- Department of Electrical and Computer Engineering, Shinshu University, 4-17-1 Wakasato, Nagano380-8553, Japan
| | - Satoshi Kato
- Department of Electrical and Computer Engineering, Shinshu University, 4-17-1 Wakasato, Nagano380-8553, Japan
| | - Jing Xia
- Department of Electrical and Computer Engineering, Shinshu University, 4-17-1 Wakasato, Nagano380-8553, Japan
| | - Motohiko Ezawa
- Department of Applied Physics, The University of Tokyo, 7-3-1 Hongo, Tokyo113-8656, Japan
| | - Oleg A Tretiakov
- School of Physics, The University of New South Wales, Sydney2052, Australia
| | - Zhipeng Hou
- South China Academy of Advanced Optoelectronics, South China Normal University, Guangzhou510006, China
| | - Yan Zhou
- School of Science and Engineering, The Chinese University of Hong Kong, Shenzhen518172, Guangdong, China
| | - Guoping Zhao
- College of Physics and Electronic Engineering, Sichuan Normal University, Chengdu610068, China
| | - Jinbo Yang
- State Key Laboratory for Mesoscopic Physics, School of Physics, Peking University, Beijing100871, China
| | - Xiaoxi Liu
- Department of Electrical and Computer Engineering, Shinshu University, 4-17-1 Wakasato, Nagano380-8553, Japan
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199
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Rehman MU, Qiao Z. MX family: an efficient platform for topological spintronics based on Rashba and Zeeman-like spin splittings. J Phys Condens Matter 2022; 51:015001. [PMID: 36279874 DOI: 10.1088/1361-648x/ac9d15] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/22/2022] [Accepted: 10/24/2022] [Indexed: 06/16/2023]
Abstract
Taking various combinations of M = (Mo, W) and X = (C, S, Se) as examples, we propose that MX (M = transition metals, X = IV,V or VI elements) family can establish an excellent platform for both conventional and topological spintronics applications based on anisotropic Rashba-like and non-magnetic Zeeman-type spin splittings with electrically tunable nature. In particular, we observe sizeable Zeeman-like and Rashba-like spin splittings with an anisotropic nature. Meanwhile, they exhibit Rashba-like and topologically robust helical edge states when grown in ferroelectric and paraelectric phases, respectively. These MX monolayers are realized to be quantum valley Hall insulators due to valley contrasting Berry curvatures. The carriers in these MX monolayers can be selectively excited from opposite valleys depending on the polarity of circularly polarized light. The amplitude of the spin splitting can be further tuned by applying external means such as strain, electric field or alloy engineering. Furthermore, considering graphene sheet over the WC monolayer as a prototype example, we show that these MX monolayers can boost the relativistic effect by coupling with the systems exhibiting extremely weak spin-orbit coupling (SOC). Depending on the surface of WC monolayer in contact with the graphene sheet, graphene over WC monolayer passes through the transformation from the semiconducting junction to the Shotcky barrier-free contact. Finally, we reveal that these MX monolayers could also be grown on the substrates such as WS2(001)and GaTe (001) with type-II band alignment, where electron and hole become layer splitted across the interface. Our analysis should be fairly applied to other systems with strong SOC and an equivalent geometrical structure to the MX monolayers.
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Affiliation(s)
- Majeed Ur Rehman
- CAS Key Laboratory of Strongly-Coupled Quantum Matter Physics, and Department of Physics, University of Science and Technology of China, Hefei, Anhui 230026, People's Republic of China
| | - Zhenhua Qiao
- CAS Key Laboratory of Strongly-Coupled Quantum Matter Physics, and Department of Physics, University of Science and Technology of China, Hefei, Anhui 230026, People's Republic of China
- ICQD, Hefei National Research Center for Physical Sciences at Microscale, University of Science and Technology of China, Hefei, Anhui 230026, People's Republic of China
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200
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Cubukcu M, Pöllath S, Tacchi S, Stacey A, Darwin E, Freeman CWF, Barton C, Hickey BJ, Marrows CH, Carlotti G, Back CH, Kazakova O. Manipulation of Magnetic Skyrmion Density in Continuous Ir/Co/Pt Multilayers. Micromachines (Basel) 2022; 13:1911. [PMID: 36363931 PMCID: PMC9693305 DOI: 10.3390/mi13111911] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 09/30/2022] [Revised: 10/27/2022] [Accepted: 11/02/2022] [Indexed: 06/16/2023]
Abstract
We show that magnetic skyrmions can be stabilised at room temperature in continuous [Ir/Co/Pt]5 multilayers on SiO2/Si substrates without the prior application of electric current or magnetic field. While decreasing the Co thickness, a transition of the magnetic domain patterns from worm-like state to separated stripes is observed. The skyrmions are clearly imaged in both states using magnetic force microscopy. The density of skyrmions can be significantly enhanced after applying the "in-plane field procedure". Our results provide means to manipulate magnetic skyrmion density, further allowing for the optimised engineering of skyrmion-based devices.
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Affiliation(s)
- M. Cubukcu
- National Physical Laboratory, Teddington TW11 0LW, UK
- London Centre for Nanotechnology, University College London, 17-19 Gordon Street, London WC1H 0AH, UK
| | - S. Pöllath
- Institut für Experimentelle Physik, Universität Regensburg, D-93040 Regensburg, Germany
| | - S. Tacchi
- Istituto Officina dei Materiali del CNR (CNR-IOM), Sede Secondaria di Perugia, c/o Dipartimento di Fisica e Geologia, Università di Perugia, I-06123 Perugia, Italy
| | - A. Stacey
- School of Physics and Astronomy, University of Leeds, Leeds LS2 9JT, UK
| | - E. Darwin
- School of Physics and Astronomy, University of Leeds, Leeds LS2 9JT, UK
| | - C. W. F. Freeman
- National Physical Laboratory, Teddington TW11 0LW, UK
- London Centre for Nanotechnology, University College London, 17-19 Gordon Street, London WC1H 0AH, UK
| | - C. Barton
- National Physical Laboratory, Teddington TW11 0LW, UK
| | - B. J. Hickey
- School of Physics and Astronomy, University of Leeds, Leeds LS2 9JT, UK
| | - C. H. Marrows
- School of Physics and Astronomy, University of Leeds, Leeds LS2 9JT, UK
| | - G. Carlotti
- Dipartimento di Fisica e Geologia, Università di Perugia, Via Pascoli, I-06123 Perugia, Italy
| | - C. H. Back
- Physik-Department, Technical University Munich, 85748 Garching, Germany
| | - O. Kazakova
- National Physical Laboratory, Teddington TW11 0LW, UK
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