Quantum dynamics in electron-nuclei coupled spin system in quantum dots: Bunching, revival, and quantum correlation in electron-spin measurements

TL;DR

This paper explores quantum correlations in electron-nuclei spin systems within quantum dots, revealing phenomena like measurement outcome bunching, state revival, and nuclear spin squeezing through successive electron spin measurements.

Contribution

It introduces a novel understanding of quantum correlations and measurement-induced effects in electron-nuclei coupled systems in quantum dots, applicable to various quantum dot configurations.

Findings

Observation of outcome bunching in electron spin measurements

Demonstration of state revival in electron spins

Nuclear spin squeezing via conditional measurements

Abstract

We investigate quantum dynamics in the electron-nuclei coupled spin system in quantum dots and clarify the fundamental features of quantum correlation induced via successive electron spin measurements. This quantum correlation leads to interesting phenomena such as the bunching of outcomes in the electron spin measurements and the revival of an arbitrary initial electron spin state. The nuclear spin system is also affected by the quantum correlation and is in fact squeezed via conditional measurements or postselection. This squeezing is confirmed by calculating the increase in the purity of the nuclear spin system. Thus the successive electron spin measurements provide a probabilistic method to squeeze the nuclear spin system. These new features are predicted not only for the case of a double quantum dots occupied by a pair of electrons but also for the case of a single quantum dot occupied by a single electron or a pair of electrons.