Spin relaxation in semiconductor quantum dots

TL;DR

This paper investigates the mechanisms of spin-flip relaxation in GaAs quantum dots, revealing that their zero-dimensional nature significantly suppresses spin-flip rates due to crystal and interface symmetry effects.

Contribution

It provides detailed calculations of spin-flip rates considering spin-orbit coupling in quantum dots, highlighting the impact of their zero-dimensional confinement on spin relaxation.

Findings

Spin-flip rates are unusually low in GaAs quantum dots.

Zero-dimensional confinement suppresses effective spin-flip mechanisms.

Crystal and interface symmetries contribute to spin-flip rate reduction.

Abstract

We have studied the physical processes responsible for the spin -flip in GaAs quantum dots. We have calculated the rates for different mechanisms which are related to spin-orbit coupling and cause a spin-flip during the inelastic relaxation of the electron in the dot both with and without a magnetic field. We have shown that the zero-dimensional character of the problem when electron wave functions are localized in all directions leads to freezing out of the most effective spin-flip mechanisms related to the absence of the inversion centers in the elementary crystal cell and at the heterointerface and, as a result, to unusually low spin-flip rates.