Controlling hole spins in quantum dots and wells

TL;DR

This paper reviews recent theoretical advances in controlling hole spins in quantum wells and dots, focusing on spin-orbit coupling, Coulomb interactions, and decoherence mechanisms unique to hole systems.

Contribution

It provides a comprehensive overview of the effects of spin-orbit coupling and Coulomb interactions on hole spins, and discusses methods to control decoherence in quantum dot systems.

Findings

Spin-orbit coupling significantly affects hole spin dynamics.

Coulomb interactions influence spin-dependent quasiparticle velocities.

Motional-averaging can mitigate hyperfine-induced decoherence.

Abstract

We review recent theoretical results for hole spins influenced by spin-orbit coupling and Coulomb interaction in two-dimensional quantum wells as well as the decoherence of single hole spins in quantum dots due to hyperfine interaction with surrounding nuclear spins. After reviewing the different forms of spin-orbit coupling that are relevant for electrons and heavy holes in III-V semiconductor quantum wells, we illustrate the combined effect of spin-orbit coupling and Coulomb interactions for hole systems on spin-dependent quasiparticle group velocities. We further analyze spin-echo decay for a single hole spin in a nuclear-spin bath, demonstrating that this decoherence source can be controlled in these systems by entering a motional-averaging regime. Throughout this review, we emphasize physical effects that are unique to hole spins (rather than electrons) in nanoscale systems.