2020 Fiscal Year Research-status Report
Current-driven dynamics of non-collinear antiferromagnetic spin structures for functional spintronic devices
| Project/Area Number |
20K15155
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| Research Institution | Tohoku University |
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Principal Investigator |
DUTTAGUPTA SAMIK 東北大学, 先端スピントロニクス研究開発センター, 助教 (30807657)
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| Project Period (FY) |
2020-04-01 – 2024-03-31
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| Keywords | AFM spintronics / Weyl semimetals / Topology |
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| Outline of Annual Research Achievements |
The concerted effort of relativistic spin-orbit interaction, electronic band topology and magnetic order in antiferromagnetic Weyl semimetals (WSM-AFMs) manifests itself in novel properties, crucial for development of antiferromagnetic spintronics. We have quantified magnetotransport properties of polycrystalline and epitaxial WSM-AFM/heavy-metal structures. Planar Hall effect measurements show a considerable anisotropic behavior between the crystallographic orientations (C and M-plane) of the epitaxial structure and a significantly larger magnitude compared to that of the polycrystalline one. Our observations reveal the signatures of chiral anomaly in condensed matter systems and shows an electronic route towards characterization of topological materials.
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| Current Status of Research Progress |
Current Status of Research Progress
1: Research has progressed more than it was originally planned.
Reason
Our current research work deals with the interplay of relativistic spin-orbit interaction and non-collinear antiferromagnetic order leading to novel spin-dependent topological magnetoresistive effects and corresponds to the first objective of the proposed work plan. In addition, our present results have also provided significant insights into the manifestation of the band structure topology as a function of the antiferromagnet thickness and heavy-metal (HM) underlayer in antiferromagnetic Weyl semimetal/HM structures. In our current work, we are investigating new routes towards control of the topological properties for the realization of high-performance antiferromagnetic spintronic devices.
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| Strategy for Future Research Activity |
The proposed work can be divided into three stages: (1) quantification and control of the topological properties in non-collinear Weyl semimetal antiferromagnet (WSM-AFM), (2) current-induced control of WSM-AFM spin structures, and (3) realization and current-induced control of WSM-AFM spin textures. At this stage, our results enable magnetoresistive quantification of the topological properties and have provided significant insights towards its control. Subsequent investigations concern current-induced control of WSM-AFM spin structures for development of next-generation antiferromagnetic spintronic devices.
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| Causes of Carryover |
The proposed grant amount was originally planned for the purchase of sputtering targets, single crystalline substrates, and process gas for experiments. However, in the last year, we have been able to achieve our proposed objective in a significantly quick time scale as originally planned. The incurring amount will be utilized this FY for purchase of experimental items (sample fabrication, and electronic measurements) such as process gas, sputtering targets, single-crystalline targets, coaxial cables for high-speed electronic measurements, He gas for physical property measurement system.
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[Presentation] Dynamics of synthetic antiferromagnetic skyrmion from current-induced deterministic motion to thermally-activated diffusive motion2021
Author(s)
T. Dohi, S. DuttaGupta, F. Kammerbauer, N. Kerber, B. Seng, Y. Ge, K. Raab, R. Gruber, M. Brems, J. Rothorl, P. Virnau, S. Fukami, M. Klaui and H. Ohno
Organizer
Intermag 2021 (virtual conference)
Int'l Joint Research
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