[14a-C41-1~6] 10.2 Spin torque, spin current, circuits, and measurement technologies

▼ [14a-C41-3] Prediction of the Enhanced Edelstein effect using the interband Rashba effect in InAlAs/InGaAs/InAlAs/InGaAs/InAlAs double quantum wells

〇(M1)Kiminori Okamoto¹, Atsushi Sawada¹, Carlos Egues², Takaaki Koga¹ (1.Hokkaido Univ., 2.sao paulo Univ.)

Keywords:spin current, spin orbit interaction, theory

We proposed an enhanced spin-blocking effect analogous to the Edelstein effect, which is current-induced spin polarization in the presence of the spin orbit interaction such as the Rashba effect assuming the device, which consist of (001) InP lattice-matched InGaAs/InAlAs double quantum wells. Spin generation in nonmagnetic semiconductor is attracting interest not only in terms of application but also basic science. In our device, we can control the site potentials at each quantum well by top gate voltage and at an appropriate top gate voltages, we can selectively scatter the electron with one spin and with the other one go through in the device. We first considered the electron with k_y = 0 (one-dimensional model along x), which is assumed to contribute most to the bulk electrical current, and failed to generate spin polarization. Then we considered all k’s including k_y ≠ 0 (two-dimensional model) and calculated the expected value of spin polarization P by summing up over k_y, and we can obtain P = 17% purely electrically. This means that we can generate current-induced spin polarization, i.e., the Edelstein effect in enhanced manner (10⁴ times larger than available experimental value). An intriguing question, which k_y contributes the most to the spin polarization is investigated in present work.