Quantum Dynamics of Electron-Nuclei Coupled System in Quantum Dots

TL;DR

This paper explores the quantum dynamics of coupled electron-nuclear systems in quantum dots, revealing nuclear spin memory effects, spin state squeezing, and proposing methods to prepare and detect nuclear superposition states through electron spin measurements.

Contribution

It introduces new mechanisms for nuclear spin state manipulation and detection using electron spin measurements in quantum dots, including superposition state preparation.

Findings

Nuclear spin memory evidenced by electron spin measurement bunching and revival.

Nuclear spin state squeezing and correlations observed.

Quantum interference effects detectable in unpolarized nuclear spins.

Abstract

We have investigated the dynamics of the electron-nuclei coupled system in quantum dots. The bunching of results of the electron spin measurements and the revival in the conditional probabilities are salient features of the nuclear spin memory. The underlying mechanism is the squeezing of the nuclear spin state and the correlations between the successive electron spin measurements. Further we make a proposal for the preparation and detection of superposition states of nuclear spins merely relying on electron spin measurements. For unpolarized, completely random nuclear spin state one can still trace the quantum interference effects. We discuss the realization of these schemes for electron spins on both single and double QDs.