Influcence of the nuclear electric quadrupolar interaction on the coherence time of hole- and electron-spins confined in semiconductor quantum dots

TL;DR

This paper investigates how nuclear electric quadrupolar interactions influence the coherence times of electron and hole spins in semiconductor quantum dots, combining theoretical calculations with experimental validation.

Contribution

It extends the central spin model to include quadrupolar interactions and compares theoretical predictions with experimental spin noise spectra for the first time.

Findings

Quadrupolar interactions significantly affect spin coherence times.

Electron and hole spin noise spectra differ due to spectral sum rule.

Experimental spectra confirm theoretical predictions.

Abstract

The real-time spin dynamics and the spin noise spectra are calculated for p and n-charged quantum dots within an anisotropic central spin model extended by additional nuclear electric quadrupolar interactions (QC) and augmented by experimental data studied using identical excitation conditions. Using realistic estimates for the distribution of coupling constants including an anisotropy parameter, we show that the characteristic long time scale is of the same order for electron and hole spins strongly determined by the QC even though the analytical form of the spin decay differs significantly consistent with our measurements. The low frequency part of the electron spin noise spectrum is approximately $1/3$ smaller than those for hole spins as a consequence of the spectral sum rule and the different spectral shapes. This is confirmed by our experimental spectra measured on both types of quantum dot ensembles in the low power limit of the probe laser.