2017 Fiscal Year Annual Research Report
TAILORING SPIN-ORBIT INTERACTIONS FOR NEUROMORPHIC COMPUTING WITH MAGNETIC DOMAIN WALL MOTION
| Project/Area Number |
17H06511
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| Research Institution | Tohoku University |
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Principal Investigator |
DUTTAGUPTA SAMIK 東北大学, スピントロニクス学術連携研究教育センター, 教育研究支援者 (30807657)
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| Project Period (FY) |
2017-08-25 – 2019-03-31
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| Keywords | spin orbit torque / Dzyaloshinskii Moriya / antiferromagnet |
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| Outline of Annual Research Achievements |
Quantification of spin-orbit torques (SOT) and Dzyaloshinskii-Moriya interaction (DMI) in ferromagnet (FM) multilayer stacks is the first step towards realization of sustainable neuromorphic architecture. We have previously shown the capabilities of antiferromagnet (AFM)/FM based heterostructures as an attractive candidate for neuromorphic hardware Here, we quantify strength of SOTs by using dc magneto-transport and DMI from current-induced domain wall motion measurements. Our results show sizeable SOT (effective spin Hall angle ~ 0.2) and DMI (DMI constant ~ 0.024 mJ/m2) in Pt0.38Mn0.62/[Co/Ni] heterostructure. The obtained information provides crucial insights for design of device structure using AFM/FM.
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| Current Status of Research Progress |
Current Status of Research Progress
2: Research has progressed on the whole more than it was originally planned.
Reason
In our previous work, we have addressed the first part of the proposed work plan. In addition, the previous works have also unfolded major roles played by the AFM underlayer towards device operation. For instance, neuromorphic synaptic capabilities of an AFM/FM heterostructure depends on the intricate details of AFM domain structure which might affect domain wall propagation in the adjacent FM layer. In our current work, we are investigating the structure-property relationship of the AFM Pt0.38Mn0.62 for design of best performance device functionalities.
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| Strategy for Future Research Activity |
The proposed work can be divided in three steps: (1) quantification of underlying interactions required for operation, (2) designing of suitable device structure and (3) demonstration of functionalities. We are currently investigating the correlation of the AFM structure to spin-orbit interactions in solely-AFM and AFM/FM based heterostructures. The characterization of AFM underlayer will provide major insights enabling the realization of robust neuromorphic architecture. In addition, the possibility of ferro-magnet free AFM heterostructures for neuromorphic architectures will also be addressed.
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