Electron spin relaxation in cubic GaN quantum dots

TL;DR

This study investigates electron spin relaxation times in cubic GaN quantum dots, highlighting the dominant hyperfine interaction mechanism over spin-orbit coupling due to GaN's small spin-orbit interaction.

Contribution

It systematically compares two key spin relaxation mechanisms in GaN quantum dots, emphasizing the hyperfine process's significance over spin-orbit coupling.

Findings

Hyperfine interaction dominates spin relaxation in GaN quantum dots.

Spin relaxation times vary with magnetic field, well width, and quantum dot size.

Hyperfine process is more important in GaN than in GaAs or InAs.

Abstract

The spin relaxation time $T_{1}$ in zinc blende GaN quantum dot is investigated for different magnetic field, well width and quantum dot diameter. The spin relaxation caused by the two most important spin relaxation mechanisms in zinc blende semiconductor quantum dots, {i.e.} the electron-phonon scattering in conjunction with the Dresselhaus spin-orbit coupling and the second-order process of the hyperfine interaction combined with the electron-phonon scattering, are systematically studied. The relative importance of the two mechanisms are compared in detail under different conditions. It is found that due to the small spin orbit coupling in GaN, the spin relaxation caused by the second-order process of the hyperfine interaction combined with the electron-phonon scattering plays much more important role than it does in the quantum dot with narrower band gap and larger spin-orbit coupling, such as GaAs and InAs.