Dynamic spin transport in nonmagnetic semiconductor systems

We present a brief review to our recent study concerning dynamic spin transport induced by AC-biased gate in low-dimensional semiconductor systems, in which dynamic spin-orbit interaction plays a crucial role. We construct a Boltzmann spin-transport model and a spin-drift-diffusion model to describe the time-dependent spin transport starting with the framework of Keldysh formalism. Methods for the generation and direct detection of spin current are proposed without optical and magnetic mediators.