Deciphering spin-orbit torque in magnetic single layers: Towards spin-torque devices with extended scalability

2021 Fiscal Year Final Research Report

• Project/Area Number: 20K15156
• Research Category: Grant-in-Aid for Early-Career Scientists
• Allocation Type: Multi-year Fund
• Review Section: Basic Section 29010:Applied physical properties-related
• Research Institution: Tohoku University
• Principal Investigator: LAU Yongchang 東北大学, 金属材料研究所, 特任助教 (60795764)
• Project Period (FY): 2020-04-01 – 2022-03-31
• Keywords: Compensated ferrimagnet / Spin-orbit torque / Spin-orbitronics / Spin caloritronics / Anomalous Nernst effect

Outline of Final Research Achievements

The main achievements of this project include: (1) Realizing two types of manganese and ruthenium-based alloys showing high tunability of properties by varying composition, temperature, and strain. Unlike the usual magnetic materials, these alloys with very limited magnetic response can however generate a large electrical signal from an electric field or a temperature gradient. (2) Providing evidence that domain twinning control will closely influence the spin-orbit torque in magnetic single layers. However, producing twinning-free samples remains to be a challenge. (3) Revealing material design principles for realizing efficient charge-to-spin conversion using the spin Hall effect. (4) Applying the knowledge from (3) to demonstrate large spin Hall effect in various material systems.

Free Research Field

スピントロニクス

Academic Significance and Societal Importance of the Research Achievements

我々は現在"Big Data"時代へと突入し、高い書換耐性と低消費電力を備える低コストな超高密度データストレージへの要望が高まっている。本研究課題は、そのような要請を満足しうる磁気ランダムアクセスメモリ技術の研究や開発に資するものである。また学術的観点からは、本研究で得られた成果は、スピンに関連した特性を発揮できる材料を設計するための指針を与え、将来の新材料開発を加速するためのガイドラインとなる。社会的な観点からは、本研究の成果は、上記の理想的なスピントロニクスメモリの実現に向けた一歩と位置付けられる。