Relaxation of hole spins in quantum dots via two-phonon processes

TL;DR

This paper theoretically explores how two-phonon processes and spin-orbit interactions contribute to spin relaxation in heavy hole quantum dots at low magnetic fields, explaining observed saturation effects.

Contribution

It introduces a theoretical model highlighting the significance of two-phonon processes in spin relaxation, providing insights into mechanisms at low magnetic fields.

Findings

Two-phonon processes significantly affect spin relaxation rates.

The model explains the saturation of relaxation rates at low magnetic fields.

Proposes experiments to distinguish relaxation mechanisms.

Abstract

We investigate theoretically spin relaxation in heavy hole quantum dots in low external magnetic fields. We demonstrate that two-phonon processes and spin-orbit interaction are experimentally relevant and provide an explanation for the recently observed saturation of the spin relaxation rate in heavy hole quantum dots with vanishing magnetic fields. We propose further experiments to identify the relevant spin relaxation mechanisms in low magnetic fields.