Voltage control of electron-nuclear spin correlation time in a single quantum dot

TL;DR

This paper demonstrates how bias voltage can control the hyperfine interaction and nuclear spin dynamics in a single InAs quantum dot, affecting nuclear polarization and electron spin depolarization behaviors.

Contribution

It introduces a method to electrically tune hyperfine coupling and nuclear spin relaxation times in a quantum dot, enabling control over spin dynamics.

Findings

Bias voltage modulates hyperfine coupling and nuclear spin relaxation.

Switching magnetic field orientation changes spin depolarization behavior.

Dynamic nuclear polarization amplitude is controlled via bias in magnetic fields.

Abstract

We demonstrate bias control of the hyperfine coupling between a single electron in an InAs quantum dot and the surrounding nuclear spins monitored through the positively charged exciton X+ emission. In applied longitudinal magnetic fields we vary simultaneously the correlation time of the hyperfine interaction and the nuclear spin relaxation time and thereby the amplitude of the achieved dynamic nuclear polarization under optical pumping conditions. In applied transverse magnetic fields a change in the applied bias allows to switch from the anomalous Hanle effect to the standard electron spin depolarization curves.