Overcoming phonon-induced dephasing for indistinguishable photon sources

TL;DR

This paper investigates phonon-induced decoherence in quantum dot single photon sources and proposes a three-level Raman process to mitigate its effects, enhancing photon indistinguishability for quantum technologies.

Contribution

It introduces a microscopic model and demonstrates how a three-level Raman process can overcome phonon-induced dephasing in quantum dot photon sources.

Findings

Phonon interactions cause decoherence in quantum dot photon emission.

A three-level Raman process can mitigate phonon effects.

Enhanced photon indistinguishability is achievable above a certain threshold.

Abstract

Reliable single photon sources constitute the basis of schemes for quantum communication and measurement based quantum computing. Solid state single photon sources based on quantum dots are convenient and versatile but the electronic transitions that generate the photons are subject to interactions with lattice vibrations. Using a microscopic model of electron-phonon interactions and a quantum master equation, we here examine phonon-induced decoherence and assess its impact on the rate of production, and indistinguishability, of single photons emitted from an optically driven quantum dot system. We find that, above a certain threshold of desired indistinguishability, it is possible to mitigate the deleterious effects of phonons by exploiting a three-level Raman process for photon production.