Photon scattering from a quantum acoustically modulated two-level system

TL;DR

This paper models photon scattering from a two-level quantum system coupled to phonons, revealing how optical excitation can generate specific quantum phonon states and providing a comprehensive quantum mechanical analysis of the system.

Contribution

It introduces a fully quantum mechanical model of photon-phonon interactions in a two-level system without approximations, enabling detailed state evolution analysis.

Findings

Photon scattering spectra predicted for quantum phonon states

Phonon mode is driven into characteristic quantum states

Model validated against classical phonon limit results

Abstract

We calculate the resonance fluorescence signal of a two-level system coupled to a quantized phonon mode. By treating the phonons in the independent boson model and not performing any approximations in their description, we also have access to the state evolution of the phonons. We confirm the validity of our model by simulating the limit of an initial quasi-classical coherent phonon state, which can be compared to experimentally confirmed results in the semiclassical limit. In addition we predict photon scattering spectra in the limit of purely quantum mechanical phonon states by approaching the phononic vacuum. Our method further allows us to simulate the impact of the light scattering process on the phonon state by calculating Wigner functions. We show that the phonon mode is brought into characteristic quantum states by the optical excitation process.