Investigation of methods for controlling physical properties by using spin currents

2014 Fiscal Year Final Research Report

• Project/Area Number: 23244071
• Research Category: Grant-in-Aid for Scientific Research (A)
• Allocation Type: Single-year Grants
• Section: 一般
• Research Field: Condensed matter physics II
• Research Institution: The University of Tokyo
• Principal Investigator: OTANI Yoshichika 東京大学, 物性研究所, 教授 (60245610)
• Co-Investigator(Kenkyū-buntansha): NIIMI Yasuhiro 東京大学, 物性研究所, 助教 (00574617) ; FUKUMA Yasuhiro 理化学研究所, 基幹研究所, 研究員 (90513466)
• Project Period (FY): 2011-04-01 – 2015-03-31
• Keywords: スピン流 / スピンホール効果 / スピン吸収 / スピン注入 / スピン緩和

Outline of Final Research Achievements

We have investigated methods for controlling magnetic properties using spin currents and obtained following results: We have succeeded in fully describing spin current properties including the anisotropic spin absorption in lateral spin valves, which enables one to elucidate intrinsic spin relaxation mechanisms in nonmagnets. We have designed the best material exhibiting large spin Hall angle based on the first principle calculation and experimentally demonstrated that Cu-Bi dilute alloys exhibited a giant spin Hall angle, charge to spin currents interconversion efficiency of about 24%. Spin torque ferromagnetic resonance experiments demonstrated that the effective damping constant of Permalloy can be modulated 20% via the spin Hall effect of platinum. We have succeeded in injecting quasi particle mediated spin currents into superconducting niobium and discovered the spin lifetime was enhanced by 400%. This achievement led to the quasi-particle mediated giant spin Hall effect.

Free Research Field

スピントロニクス