Semiclassical theory of weak antilocalization and spin relaxation in ballistic quantum dots

TL;DR

This paper develops a semiclassical framework for understanding spin-dependent quantum transport in ballistic quantum dots, revealing how classical dynamics influence weak antilocalization and spin relaxation effects.

Contribution

It introduces a generalized semiclassical Landauer approach that incorporates spin-orbit and Zeeman interactions, providing new insights into quantum corrections in ballistic quantum dots.

Findings

Weak antilocalization is suppressed in integrable systems.

Quantum correction sensitivity depends on classical dynamics.

Different spin relaxation mechanisms in integrable vs chaotic cavities.

Abstract

We develop a semiclassical theory for spin-dependent quantum transport in ballistic quantum dots. The theory is based on the semiclassical Landauer formula, that we generalize to include spin-orbit and Zeeman interaction. Within this approach, the orbital degrees of freedom are treated semiclassically, while the spin dynamics is computed quantum mechanically. Employing this method, we calculate the quantum correction to the conductance in quantum dots with Rashba and Dresselhaus spin-orbit interaction. We find a strong sensitivity of the quantum correction to the underlying classical dynamics of the system. In particular, a suppression of weak antilocalization in integrable systems is observed. These results are attributed to the qualitatively different types of spin relaxation in integrable and chaotic quantum cavities.