The role of orbital dynamics in spin relaxation and weak antilocalization in quantum dots

TL;DR

This paper develops a semiclassical theory to analyze how orbital dynamics influence spin relaxation and weak (anti)localization phenomena in quantum dots with spin-orbit coupling, revealing different behaviors in chaotic, regular, and diffusive systems.

Contribution

It introduces a novel semiclassical framework that distinguishes spin relaxation effects based on the classical orbital dynamics of quantum dots.

Findings

Integrable ballistic systems can show weak localization at typical Rashba coupling.

Chaotic systems tend to exhibit weak antilocalization.

Magnetoconductance suppression depends on quantum dot size and in-plane magnetic field.

Abstract

We develop a semiclassical theory for spin-dependent quantum transport to describe weak (anti)localization in quantum dots with spin-orbit coupling. This allows us to distinguish different types of spin relaxation in systems with chaotic, regular, and diffusive orbital classical dynamics. We find, in particular, that for typical Rashba spin-orbit coupling strengths, integrable ballistic systems can exhibit weak localization, while corresponding chaotic systems show weak antilocalization. We further calculate the magnetoconductance and analyze how the weak antilocalization is suppressed with decreasing quantum dot size and increasing additional in-plane magnetic field.