Collective Nuclear Stabilization by Optically Excited Hole in Quantum Dot

TL;DR

This paper introduces a method where optically exciting a heavy hole in a quantum dot induces a collective nuclear spin state, significantly enhancing electron spin coherence without directly manipulating the qubit.

Contribution

It presents a novel approach to reduce decoherence in quantum dots by controlling the environment through optical excitation of holes, addressing open problems from recent experiments.

Findings

Nuclear spins can be stabilized via optical excitation of holes.

Prolonged electron spin coherence times demonstrated.

Provides a unified solution to previous experimental challenges.

Abstract

We propose that an optically excited heavy hole in a quantum dot can drive the surrounding nuclear spins into a quiescent collective state, leading to significantly prolonged coherence time for the electron spin qubit. This provides a general paradigm to combat decoherence by environmental control without involving the active qubit in quantum information processing. It also serves as a unified solution to some open problems brought about by two recent experiments [X. Xu et al., Nature 459, 1105 (2009) and C. Latta et al., Nature Phys. 5, 758 (2009)].