Development of a high-resolution surface magnetic optical Kerr effect measurements system and its application to spin transport measurements in surface Rashba systems

2015 Fiscal Year Final Research Report

• Project/Area Number: 25600093
• Research Category: Grant-in-Aid for Challenging Exploratory Research
• Allocation Type: Multi-year Fund
• Research Field: Thin film/Surface and interfacial physical properties
• Research Institution: Tokyo Institute of Technology (2014-2015); The University of Tokyo (2013)
• Principal Investigator: Hirahara Toru 東京工業大学, 理工学研究科, 准教授 (30451818)
• Project Period (FY): 2013-04-01 – 2016-03-31
• Keywords: 物性実験 / 表面・界面物性 / ラシュバ効果

Outline of Final Research Achievements

The purpose of this research is to measure the spin transport phenomenon at the surface of nonmagnetic materials which exhibit large Rashba splitting. Due to the spin-momentum locking in these systems, they are expected to show dichroism behavior when irradiated with left/right circularly-polarized light that originate from the peculiar band structure (spin galvanic effect). First, we have irradiated circularly-polarized visible laser on the Bi(111) films and Ag(111)√3×√3-Bi which show large Rashba splitting. We succeeded in measuring the dichroism behavior by precisely measuring the electromotive force between the two edges of the samples. However, we also observed dichroism behavior for the Si(111)7×7 surface which we did not expect. Secondly, we tried to measure the current-induced spin-polarization of the Rashba systems with spin-polarized He ion scattering. We succeeded in observing the spin-dependent scattering phenomenon that originate from spin-orbit coupling.

Free Research Field

表面・界面物理