Excitation of spin density and current by coherent light pulses in QWs

TL;DR

This paper investigates how coherent light pulses can induce spin polarization and electric currents in semiconductor quantum wells, with effects controllable by pulse parameters and external magnetic fields.

Contribution

It demonstrates the control of spin and charge dynamics in quantum wells using coherent optical pulses and interference effects, revealing new ways to manipulate spintronics properties.

Findings

Optical pulses induce spin orientation and electric current in QWs.

Carrier distributions depend on crystallographic orientation and pulse parameters.

External magnetic fields influence the induced spin and current dynamics.

Abstract

We study the orbital and spin dynamics of charge carriers induced by non-overlapping linearly polarized light pulses in semiconductor quantum wells (QWs). It is shown that such an optical excitation with coherent pulses leads to a spin orientation of photocarriers and an electric current. The effects are caused by the interference of optical transitions driven by individual pulses. The distribution of carriers in the spin and momentum spaces depends on the QW crystallographic orientation and can be efficiently controlled by the pulse polarizations, time delay and phase shift between the pulses, as well as an external magnetic field.