Spin polarized electric currents in semiconductor heterostructures induced by microwave radiation

TL;DR

This paper demonstrates how microwave radiation can induce spin-polarized electric currents in semiconductor quantum wells through spin-dependent energy relaxation and magnetic field effects.

Contribution

It reveals a novel mechanism for generating spin-polarized currents via microwave-induced spin relaxation in semiconductor heterostructures.

Findings

Microwave radiation induces electric currents in quantum wells.

Spin-dependent energy relaxation creates pure spin currents.

Magnetic fields convert spin flows into spin-polarized electric currents.

Abstract

We report on microwave (mw) radiation induced electric currents in (Cd,Mn)Te/(Cd,Mg)Te and InAs/(In,Ga)As quantum wells subjected to an external in-plane magnetic field. The current generation is attributed to the spin-dependent energy relaxation of electrons heated by mw radiation. The relaxation produces equal and oppositely directed electron flows in the spin-up and spin-down subbands yielding a pure spin current. The Zeeman splitting of the subbands in the magnetic field leads to the conversion of the spin flow into a spin-polarized electric current.