Hole spin-flip transitions in a self-assembled quantum dot

Abstract

In this work, we investigate hole spin-flip transitions in a single self-assembled InGaAs/GaAs quantum dot. We find the hole wave functions using the 8-band k • p model and calculate phononassisted spin relaxation rates for the ground-state Zeeman doublet. We systematically study the importance of various admixture-and direct spin-phonon mechanisms giving rise to the transition rates. We show that the biaxial and shear strain constitute dominant spin-admixture coupling mechanisms. Then, we demonstrate that hole spin lifetime can be increased if a quantum dot is covered by a strain-reducing layer. Finally, we show that the spin relaxation can be described by an effective model.