Effect of phonon coupling on the generated entangled states of photons from a single quantum dot embedded inside a microcavity

TL;DR

This paper investigates how phonon interactions affect the quality of entangled photon states generated from a quantum dot in a microcavity, revealing conditions under which entanglement remains robust or degrades.

Contribution

It provides a detailed analysis of phonon coupling effects on entanglement in quantum dot photon sources, highlighting the role of anisotropic energy gaps and temperature.

Findings

Concurrence is maximized without anisotropic energy gap.

Entanglement remains unaffected by phonon coupling when the gap is zero.

Higher phonon bath temperatures reduce entanglement with finite energy gaps.

Abstract

We discuss the generation of two types of entangled state of two photons-- noon state which is entangled in number and polarization, and polarization entangled state which is entangled in polarization and frequency. We consider a single quantum dot coupled with a bimodal cavity in strong coupling regime. We analyze the effect of exciton-phonon coupling on the concurrence of the generated entangled states. We find that for both states concurrence is maximum in the absence of the anisotropic energy gap between exciton states and remains unchanged in the presence of exciton-phonon coupling. However, for finite anisotropic energy gap concurrence decreases on the increasing temperature of phonon bath.