Phonon statistics in an acoustical resonator coupled to a pumped two-level emitter

TL;DR

This paper models a quantum dot in an acoustical nanocavity to demonstrate quantum features in phonon statistics, specifically sub-Poissonian behavior, indicating non-classical sound vibrations.

Contribution

It presents a detailed theoretical analysis of a phonon laser system with quantum properties, extending previous acoustic laser concepts into the quantum regime.

Findings

Phonon statistics show sub-Poissonian behavior.

Quantum features of sound vibrations are demonstrated.

Strong QD-phonon coupling regime analyzed beyond secular approximation.

Abstract

The concept of an acoustical analog of the optical laser has been developed recently both in theoretical as well as experimental works. We discuss here a model of a coherent phonon generator with a direct signature of quantum properties of the sound vibrations. The considered setup is made of a laser driven quantum dot (QD) embedded in an acoustical nanocavity. The system's dynamics is solved for a single phonon mode in the steady-state and in the strong QD-phonon coupling regime beyond the secular approximation. We demonstrate that the phonon statistics exhibits quantum features, i.e. sub-Poissonian phonon statistics.