[18p-E216-1~10] 10.4 Semiconductor spintronics, superconductor, multiferroics

[18p-E216-6] Kerr rotation spectroscopy of electron spins in GaAsBi epilayer

〇Yoji Kunihashi¹, Yusuke Tanaka¹, Haruki Sanada¹, Makoto Kohda², Junsaku Nitta², Sho Hasegawa³, Hiroyuki Nishinaka³, Masahiro Yoshimoto³, Hideki Gotoh¹ (1.NTT BRL, 2.Tohoku Univ., 3.Kyoto Inst. Tech.)

Keywords:GaAsBi, spin-orbit interaction, Kerr rotation

GaAsBi is a candidate material for spintronics applications in terms of spin control via spin-orbit effective magnetic fields because the addition of bismuth atoms to GaAs crystal significantly enhances the spin-splitting energy [1]. However, to date, the research on spin dynamics in such diluted bismide has been limited. Here, we investigate the electron spin dynamics in GaAs_1-xBi_x using Kerr rotation spectroscopy based on a pump-probe technique. A Kerr rotation signal was observed for a wide wavelength region of 840 to 906 nm, where the initial phase of the spin precession under an external magnetic field was changed continuously from 0 to p. This nontrivial dependence of the spin phase on the excitation wavelength implies that the spin properties are influenced by the energy band structures in GaAs_1-xBi_x, and thus our findings are beneficial as regards understanding the spin properties of diluted GaAs_1-xBi_x alloy.