The linear spectrum of a quantum dot coupled to a nano-cavity

TL;DR

This paper presents a theoretical model for the linear spectrum of a quantum dot in a nano-cavity, accounting for mechanisms like phonon interactions, and explains experimental observations of phonon sidebands affecting cavity responses.

Contribution

The paper introduces a formalism that incorporates arbitrary spectral modifications of quantum dots, including phonon interactions, within cavity quantum electrodynamics.

Findings

Phonon sidebands can sustain cavity-like peaks at moderate detuning.

The model recovers known cavity QED predictions under Lorentzian broadening.

Supports recent experimental observations of phonon effects in quantum dot spectra.

Abstract

We develop a theoretical formalism to model the linear spectrum of a quantum dot embedded in a high quality cavity, in presence of an arbitrary mechanism modifying the homogeneous spectrum of the quantum dot. Within the simple assumption of lorentzian broadening, we show how the known predictions of cavity quantum electrodynamics are recovered. We then apply our model to the case where the quantum dot interacts with an acoustic-phonon reservoir, producing phonon sidebands in the response of the bare dot. In this case, we show that the sidebands can sustain the spectral response of the cavity-like peak even at moderate dot-cavity detuning, thus supporting recent experimental findings.