Development of high-speed domain wall memory by electric field control of Rashba effect

2019 Fiscal Year Final Research Report

• Project/Area Number: 16H04325
• Research Category: Grant-in-Aid for Scientific Research (B)
• Allocation Type: Single-year Grants
• Section: 一般
• Research Field: Electronic materials/Electric materials
• Research Institution: Ibaraki University
• Principal Investigator: Komine Takashi 茨城大学, 理工学研究科(工学野), 准教授 (90361287)
• Co-Investigator(Kenkyū-buntansha): 青野 友祐 茨城大学, 理工学研究科(工学野), 准教授 (20322662) ; 原 嘉昭 茨城工業高等専門学校, 国際創造工学科, 教授 (30331979) ; 長谷川 靖洋 埼玉大学, 理工学研究科, 准教授 (60334158)
• Project Period (FY): 2016-04-01 – 2020-03-31
• Keywords: 界面 / 電界効果 / 輸送特性

Outline of Final Research Achievements

In this study, we investigated the electric field effect on transport properties of the stacked structure. On the bismuth/insulating layer interface, it was found that the transport properties change remarkably due to the interfacial strain and mixing, which are not observed in the bismuth single layer. On the ferrimagnetic layer/insulating layer interface, the layer thickness dependence of the sign inversion of the anomalous Hall effect was observed due to the interfacial strain and mixing describing the electric field. Obtaining sharp interface structure is inevitable to interpret the experimental results of transport properties.
We also investigated a novel device in which p-n junction is formed along the film thickness direction due to the electric field effect in a bismuth alloy. As a result, the feasibility of a new thermoelectric element due to the electric field effect was proposed.

Free Research Field

機能性材料，電子デバイス

Academic Significance and Societal Importance of the Research Achievements

本研究では，磁性膜/ビスマス/絶縁膜の積層構造と輸送特性の電界効果を調べた．いずれの界面においても歪みや界面ミキシングの影響で輸送特性が著しく変化することを見出したことから，積極的な歪み導入をした新規デバイスの提案，および，電界効果を得るために適切な界面構造に関する知見が得られた．一例として，ビスマス系合金における電界効果により膜厚方向にpn接合が形成される新奇デバイスの検討を行い，電界効果による新しい熱電素子の可能性を示唆した．