||福谷 克之 教授
||Observation of the Edelstein Effect using a Spin-Polarized Atomic Hydrogen Beam.
|| Nowadays, spin current is actively studied because of its characteristic behavior in topological insulators or topological superconductors and it is required to improve the efficiency of spin current injection. While the spin Hall effect is commonly used as a means of spin current detection, the Edelstein Effect (EE) has recently attracted attention for the spin current measurement. When charge current flows in the spin-polarized system, spin accumulation occurs, which is called the EE. The Inverse Edelstein Effect (IEE) is also observed, which means spin current generates charge current. We have been developing a spin-polarized atomic hydrogen beam, which emits proton with spin-polarized electron, as a tool to observe surface states. We expect that the IEE can be induced, where the spin-polarized atomic hydrogen beam causes a charge current. For this purpose, we are considering to study the Au(111) surface. Au(111) has a 2D electron system localized on the surface. Because of relativistic effect, Rashba effect emerges to the surface electronic states of Au(111) and the spin splitting occurs. Recently, it is discovered that this states also can be recognized as topological states, which called Topological Derived Surface State(TDSS). Due to spin interaction of the spin-polarized hydrogen, it is expected a charge current is induced at the Rashba-split surface. I will talk about the prediction of the effect on the TDSS and the plan of the experiment.
L. Liu and C.-F. Pai, et al.: Science 336 (2012) 555.
V. M. Edelstein: Solid State Commun. 73 (1990) 233.
 J. C. Rojas Sánchez, et al.: Nat. Commun. 4, (2013) 2944.
S. Ogura et al.: J. Vac. Soc. Jpn. 54 (2011) 192.
B. Yan, et al.: Nat. Commun. 6 (2015) 10167.