Spin relaxation of conduction electrons in (110)-grown quantum wells

TL;DR

This paper develops a theory for spin relaxation in (110)-grown quantum wells, revealing how structure asymmetry and external magnetic fields influence spin dynamics and relaxation times.

Contribution

It introduces a comprehensive theoretical model for spin relaxation in asymmetric (110) quantum wells, highlighting the effects of structure inversion asymmetry and magnetic fields.

Findings

Asymmetric structures exhibit two distinct spin relaxation lifetimes.

An in-plane spin component appears and can be tuned by gate voltage.

Magnetic field causes nonmonotonic spin density behavior due to cyclotron and Larmor effects.

Abstract

The theory of spin relaxation of conduction electrons is developed for zinc-blende-type quantum wells grown on (110)-oriented substrate. It is shown that, in asymmetric structures, the relaxation of electron spin initially oriented along the growth direction is characterized by two different lifetimes and leads to the appearance of an in-plane spin component. The magnitude and sign of the in-plane component are determined by the structure inversion asymmetry of the quantum well and can be tuned by the gate voltage. In an external magnetic field, the interplay of cyclotron motion of carriers and the Larmor precession of electron spin can result in a nonmonotonic dependence of the spin density on the magnetic field.