Spin transport on the surfaces and heterointerfaces of semiconductors and topological insulators

2014 Fiscal Year Final Research Report

• Project/Area Number: 24340069
• Research Category: Grant-in-Aid for Scientific Research (B)
• Allocation Type: Partial Multi-year Fund
• Section: 一般
• Research Field: Condensed matter physics I
• Research Institution: Kyoto University
• Principal Investigator: ARUGA Tetsuya 京都大学, 理学(系)研究科(研究院), 教授 (70184299)
• Co-Investigator(Kenkyū-buntansha): HATTA Shinichiro 京都大学, 大学院理学研究科, 助教 (70420396)
• Project Period (FY): 2012-04-01 – 2015-03-31
• Keywords: ラシュバ効果 / 単原子層

Outline of Final Research Achievements

We have developed an experimental method which enables us to measure the sheet conductivity of metallic monolayers on semiconductor surfaces for a temperature range of 5-300 K at a precision much higher than the previous methods. By using this new method in a 7-probe arrangement, we carried out a precise examination of the spin-polarized current hypothesis proposed by Silsbee for 2D Rashba electron systems. By a careful measurement, we concluded that the hypothesis is invalid.
We also studied by a 4-probe method the temperature dependence of the sheet conductivity of a Pb monolayer on Ge(111). We found that the sheet conductivity at 10 K is more than an order of magnitude larger than those of known metallic monolayers, and that the step conductivity is two orders of magnitude larger. We also found subsurface electronic states ubiquitously formed on Ge(111) covered with different elements, which is spin-split by the Rashba effect.

Free Research Field

表面科学