Classical memory effects on spin dynamics in two-dimensional systems

TL;DR

This paper analyzes classical electron spin dynamics in two-dimensional semiconductors with specific spin-orbit configurations, revealing that non-Markovian memory effects cause a long-time non-exponential decay in spin polarization.

Contribution

It demonstrates how classical memory effects influence long-time spin dynamics in 2D systems with fixed-axis spin-orbit fields, highlighting non-Markovian behavior.

Findings

Long-time spin polarization exhibits a 1/t^2 decay tail.

Memory effects lead to non-exponential spin relaxation.

Applicable to specific quantum well orientations with balanced spin-orbit couplings.

Abstract

We discuss classical dynamics of electron spin in two-dimensional semiconductors with a spin-split spectrum. We focus on a special case, when spin-orbit induced random magnetic field is directed along a fixed axis. This case is realized in III-V-based quantum wells grown in [110] direction and also in [100]-grown quantum wells with equal strength of Dresselhaus and Bychkov-Rashba spin-orbit couplings. We show that in such wells the long-time spin dynamics is determined by non-Markovian memory effects. Due to these effects the non-exponential tail $1/t^2$ appears in the spin polarization.