Hole-capture competition between a single quantum dot and an ionized acceptor

TL;DR

This study investigates how holes are captured by a quantum dot and an adjacent ionized impurity, revealing that the quantum dot has a significantly higher capture probability and that Coulomb interactions suppress simultaneous occupation.

Contribution

It provides a quantitative analysis of hole-capture probabilities and dynamics in a quantum dot-impurity system using Kerr rotation noise spectroscopy and a theoretical model.

Findings

Quantum dot has about ten times higher hole-capture probability than the impurity.

Simultaneous occupation of the quantum dot and impurity by holes is suppressed.

A theoretical model accurately describes the spin and charge noise dynamics.

Abstract

We study the competition of hole capture between an In(Ga)As quantum dot and a directly adjacent ionized impurity in view of spin-photon interfaces. The Kerr rotation noise spectroscopy at 4.2 K shows that the hole-capture probability of the In(Ga)As quantum dot is about one order of magnitude higher compared to the hole-capture probability of the ionized impurity and suggests that a simultaneous occupation of quantum dot and impurity by a hole is efficiently suppressed due to Coulomb interaction. A theoretical model of interconnected spin and charge noise allows the quantitative specification of all relevant time scales.