Strong Hyperfine-Induced Modulation of an Optically-Driven Hole Spin in an InAs Quantum Dot

TL;DR

This paper reveals that, contrary to prior assumptions, hyperfine interactions significantly influence hole spin coherence in InAs quantum dots through a nuclear feedback mechanism, causing strong modulation at nuclear precession frequencies.

Contribution

It demonstrates the impact of hyperfine interactions on hole spin coherence via a nuclear feedback effect, highlighting a previously overlooked aspect of hole spin dynamics.

Findings

Hyperfine interaction affects hole spin coherence.

Nuclear polarization modulates spin coherence.

Strong modulation occurs at nuclear precession frequency.

Abstract

Compared to electrons, holes in InAs quantum dots have a significantly weaker hyperfine interaction that leads to less dephasing from nuclear spins. Thus many recent studies have suggested that nuclear spins are unimportant for hole spin dynamics compared to electric field fluctuations. We show that the hole hyperfine interaction can have a strong effect on hole spin coherence measurements through a nuclear feedback effect. The nuclear polarization is generated through a unique process that is dependent on the anisotropy of the hole hyperfine interaction and the coherent precession of nuclear spins, giving rise to strong modulation at the nuclear precession frequency.