Tuning of the hole spin relaxation time in single self-assembled In$_{1-x}$Ga$_x$As/GaAs quantum dots by electric field

TL;DR

This paper demonstrates that applying an electric field along the growth direction of InGaAs/GaAs quantum dots can significantly tune the hole spin relaxation time, providing a controllable method for spin dynamics in quantum dot systems.

Contribution

It introduces the use of electric field tuning to control hole spin relaxation times in self-assembled quantum dots, revealing asymmetry effects related to dot height.

Findings

Electric field can change hole spin relaxation time by over an order of magnitude.

Tuning effect is asymmetric with respect to the electric field direction.

The asymmetry increases with the height of the quantum dot.

Abstract

We investigate the electric field tuning of the phonon-assisted hole spin relaxation in single self-assembled In$_{1-x}$Ga$_{x}$As/GaAs quantum dots, using an atomistic empirical pseudopotential method. We find that the electric field along the growth direction can tune the hole spin relaxation time for more than one order of magnitude. The electric field can prolong or shorten the hole spin lifetime and the tuning shows an asymmetry in terms of the field direction. The asymmetry is more pronounced for the taller the dot. The results show that the electric field is an effective way to tune the hole spin-relaxation in self-assembled QDs.