Electron Spin Dynamics in Impure Quantum Wells for Arbitrary Spin-Orbit Coupling

TL;DR

This paper provides an exact calculation of electron spin dynamics in disordered 2D systems with arbitrary Rashba spin-orbit coupling, revealing new spin decay regimes and implications for spintronic device performance.

Contribution

It offers the first exact Boltzmann formalism analysis of spin evolution for any Rashba coupling strength in disordered quantum wells, challenging classical relaxation models.

Findings

Dyakonov-Perel mechanism fails at strong Rashba fields

New regimes of spin decay are identified

Spin manipulation can be enhanced in strong spin-orbit materials

Abstract

Strong interest has arisen recently on low-dimensional systems with strong spin-orbit interaction due to their peculiar properties of interest for some spintronic applications. Here, the time evolution of the electron spin polarization of a disordered two-dimensional electron gas is calculated exactly within the Boltzmann formalism for arbitrary couplings to a Rashba spin-orbit field. The classical Dyakonov-Perel mechanism of spin relaxation is shown to fail for sufficiently strong Rashba fields, in which case new regimes of spin decay are identified. These results suggest that spin manipulation can be greatly improved in strong spin-orbit interaction materials.