Entangled photon pairs produced by a quantum dot strongly coupled to a microcavity

TL;DR

This paper theoretically demonstrates a method to generate entangled photon pairs on demand using a quantum dot strongly coupled to a microcavity, leveraging polariton states to enhance entanglement and reduce dephasing.

Contribution

It introduces a novel scheme for entangled photon pair production via biexciton decay in a strongly coupled quantum dot-microcavity system, tunable through polariton modes.

Findings

Entangled photon pairs can be produced on demand.

Strong coupling allows tuning of polariton modes.

Polariton states are protected against dephasing.

Abstract

We show theoretically that entangled photon pairs can be produced on demand through the biexciton decay of a quantum dot strongly coupled to the modes of a photonic crystal. The strong coupling allows to tune the energy of the mixed exciton-photon (polariton) eigenmodes, and to overcome the natural splitting existing between the exciton states coupled with different linear polarizations of light. Polariton states are moreover well protected against dephasing due to their lifetime ten to hundred times shorter than that of a bare exciton. Our analysis shows that the scheme proposed can be achievable with the present technology.