Influence of electron-acoustic phonon scattering on off-resonant cavity feeding within a strongly coupled quantum-dot cavity system

TL;DR

This paper develops a nonperturbative quantum optics model to analyze how electron-acoustic phonon interactions affect emission spectra in strongly coupled quantum-dot cavity systems, explaining experimental observations.

Contribution

It introduces an analytical, non-Markovian approach incorporating phonon effects to predict emission spectra in quantum-dot cavity systems, applicable to various semiconductor structures.

Findings

Demonstrates cavity emission spectral asymmetries due to phonons

Shows cavity-mode suppression and enhancement effects

Achieves good agreement with experimental data across detunings and temperatures

Abstract

We present a medium-dependent quantum optics approach to describe the influence of electron-acoustic phonon coupling on the emission spectra of a strongly coupled quantum-dot cavity system. Using a canonical Hamiltonian for light quantization and a photon Green function formalism, phonons are included to all orders through the dot polarizability function obtained within the independent Boson model. We derive simple user-friendly analytical expressions for the linear quantum light spectrum, including the influence from both exciton and cavity-emission decay channels. In the regime of semiconductor cavity-QED, we study cavity emission for various exciton-cavity detunings and demonstrate rich spectral asymmetries as well as cavity-mode suppression and enhancement effects. Our technique is nonperturbative, and non-Markovian, and can be applied to study photon emission from a wide range of semiconductor quantum dot structures, including waveguides and coupled cavity arrays. We compare our theory directly to recent and apparently puzzling experimental data for a single site-controlled quantum dot in a photonic crystal cavity and show good agreement as a function of cavity-dot detuning and as a function of temperature.