Non-exponential spin relaxation in magnetic field in quantum wells with random spin-orbit coupling

TL;DR

This paper explores how random spin-orbit coupling in quantum wells affects electron spin relaxation, revealing that magnetic fields can accelerate relaxation contrary to typical suppression effects, due to spatial randomness and memory effects.

Contribution

It demonstrates that spatial randomness in spin-orbit coupling leads to a Gaussian decay of spin polarization and modifies the magnetic field dependence of spin relaxation.

Findings

Relaxation rate is limited by spatial randomness.

Magnetic field accelerates spin relaxation in these systems.

Spin polarization decays Gaussianly over time.

Abstract

We investigate the spin dynamics of electrons in quantum wells where the Rashba type of spin-orbit coupling is present in the form of random nanosize domains. We study the effect of magnetic field on the spin relaxation in these systems and show that the spatial randomness of spin-orbit coupling limits the minimum relaxation rate and leads to a Gaussian time-decay of spin polarization due to memory effects. In this case the relaxation becomes faster with increase of the magnetic field in contrast to the well known magnetic field suppression of spin relaxation.