Impact of phonon lifetimes on the single-photon indistinguishability in quantum emitters based on 2D materials

TL;DR

This paper investigates how phonon lifetimes affect the indistinguishability of single photons emitted from 2D material-based quantum emitters, highlighting the impact of exciton-phonon interactions and cavity effects on quantum light quality.

Contribution

It provides a quantum mechanical analysis of exciton-phonon coupling and phonon lifetime effects on photon indistinguishability in 2D material quantum emitters, revealing key limitations.

Findings

Increased exciton-phonon coupling reduces photon indistinguishability in 2D systems.

Finite phonon lifetime causes pure dephasing, affecting photon coherence.

Overcoming phonon-related limitations is essential for quantum light source applications.

Abstract

Localized excitons in two-dimensional (2D) materials are considered as promising sources of single photons on demand. The photon indistinguishability as key figure of merit for quantum information processing is strongly influenced by the coupling of charge excitations to lattice vibrations of the surrounding semiconductor material. Here, we quantify the impact of exciton-acoustic-phonon-interaction and cavity QED effects on photon indistinguishability in a Hong-Ou-Mandel setup by solving fully quantum mechanical equations for the coupled QD-cavity-phonon system including non-Markovian effects. We find a strong reduction of indistinguishability compared to 3D systems due to increased exciton-phonon coupling efficiency. Moreover, we show that the coherence properties of photons are significantly influenced by the finite phonon lifetime in the surrounding material giving rise to pure dephasing. Only if these limitations are overcome, localized excitons in 2D semiconductors can become a new avenue for quantum light sources.