Spin decoherence of a heavy hole coupled to nuclear spins in a quantum dot

TL;DR

This paper theoretically investigates the interaction between heavy hole spins and nuclear spins in quantum dots, revealing significant decoherence effects and unique Ising-like interactions that impact quantum information applications.

Contribution

It demonstrates that heavy holes can have strong nuclear spin interactions, contrary to prior assumptions, and characterizes the resulting decoherence properties in unstrained quantum dots.

Findings

Heavy holes exhibit significant interaction with nuclear spins.

The interaction is Ising-like in unstrained quantum dots.

This interaction influences decoherence, affecting quantum information processing.

Abstract

We theoretically study the interaction of a heavy hole with nuclear spins in a quasi-two-dimensional III-V semiconductor quantum dot and the resulting dephasing of heavy-hole spin states. It has frequently been stated in the literature that heavy holes have a negligible interaction with nuclear spins. We show that this is not the case. In contrast, the interaction can be rather strong and will be the dominant source of decoherence in some cases. We also show that for unstrained quantum dots the form of the interaction is Ising-like, resulting in unique and interesting decoherence properties, which might provide a crucial advantage to using dot-confined hole spins for quantum information processing, as compared to electron spins.