Generation of spin current and polarization under dynamic gate control of spin-orbit interaction in low-dimensional semiconductor systems

TL;DR

This paper investigates how dynamic gate control of spin-orbit interaction in low-dimensional semiconductors can generate and manipulate spin currents and polarization, using theoretical models to explore stationary and rectified spin phenomena.

Contribution

It introduces a theoretical framework combining Keldysh formalism, Boltzmann, and drift diffusion equations to analyze spin dynamics under time-dependent Rashba interactions in quantum wells.

Findings

Identification of conditions for stationary spin density

Demonstration of rectified DC spin current generation

Analysis of spin manipulation via gate shapes

Abstract

Based on the Keldysh formalism, the Boltzmann kinetic equation and the drift diffusion equation have been derived for studying spin polarization flow and spin accumulation under effect of the time dependent Rashba spin-orbit interaction in a semiconductor quantum well. The time dependent Rashba interaction is provided by time dependent electric gates of appropriate shapes. Several examples of spin manipulation by gates have been considered. Mechanisms and conditions for obtaining the stationary spin density and the induced rectified DC spin current are studied.