Entanglement Dynamics of Molecular Exciton States in Coupled Quantum Dots

TL;DR

This paper models the electronic and entanglement dynamics of coupled quantum dots under electric fields, identifying conditions for high-fidelity entangled photon emission superior to single dots.

Contribution

It introduces a theoretical framework for entanglement in coupled quantum dots and identifies optimal regimes for entangled photon generation.

Findings

High entanglement fidelity achievable in specific detuning regimes

Coupled quantum dots outperform single dots in entangled photon emission

Fidelity remains near unity over a broad exchange splitting range

Abstract

We theoretically model the electronic dynamics of a coupled quantum dot pair in a static electric field. We then investigate the possibility of polarization-entangled photon emission from the radiative cascade of the molecular biexciton state. Through numerical simulations, we analyze the dependence of entanglement fidelity on temperature and electric field, as well as tunnel coupling. We establish a regime of direct-indirect exciton detunings for which coupled quantum dots are superior to single dots for entangled photon generation, yielding near-unit fidelity over a larger range of exchange splittings.