Engineering the impact of phonon dephasing on the coherence of a WSe$_{2}$ single-photon source via cavity quantum electrodynamics

TL;DR

This paper demonstrates how coupling a WSe₂ monolayer quantum dot to a cavity can control phonon-induced dephasing, improving photon coherence for quantum technologies.

Contribution

It introduces a method to engineer photon coherence by tuning cavity resonance with a 2D material emitter, revealing new control over phonon dephasing effects.

Findings

Spectral enhancement and suppression of phonon sidebands achieved

Cavity tuning directly influences dephasing as shown by interferometry

Excellent agreement with microscopic exciton-phonon models

Abstract

Emitter dephasing is one of the key issues in the performance of solid-state single photon sources. Among the various sources of dephasing, acoustic phonons play a central role in adding decoherence to the single photon emission. Here, we demonstrate, that it is possible to tune and engineer the coherence of photons emitted from a single WSe$_2$ monolayer quantum dot via selectively coupling it to a spectral cavity resonance. We utilize an open cavity to demonstrate spectral enhancement, leveling, and suppression of the highly asymmetric phonon sideband, finding excellent agreement with a microscopic description of the exciton-phonon dephasing in a truly two-dimensional system. Moreover, the impact of cavity tuning on the dephasing is directly assessed via optical interferometry, which points out the capability to utilize light-matter coupling to steer and design dephasing and coherence of quantum emitters in atomically thin crystals.