Regimes of strong light-matter coupling under incoherent excitation

TL;DR

This paper explores the different operational regimes of a strongly coupled light-matter system under incoherent excitation, revealing a quantum to classical transition and identifying five distinct regimes with unique spectral features.

Contribution

It introduces a classification of five regimes in strongly coupled light-matter systems under incoherent pumping, including a detailed analysis of the lasing regime as a dressed state condensation.

Findings

Identification of five regimes: linear, quantum, lasing, quenching, thermal

Lasing regime characterized by a Mollow triplet in the spectrum

Quantum to classical transition observed in the system behavior

Abstract

We study a two-level system (atom, superconducting qubit or quantum dot) strongly coupled to the single photonic mode of a cavity, in the presence of incoherent pumping and including detuning and dephasing. This system displays a striking quantum to classical transition. On the grounds of several approximations that reproduce to various degrees exact results obtained numerically, we separate five regimes of operations, that we term "linear", "quantum", "lasing", "quenching" and "thermal". In the fully quantized picture, the lasing regime arises as a condensation of dressed states and manifests itself as a Mollow triplet structure in the direct emitter photoluminescence spectrum, which embeds fundamental features of the full-field quantization description of light-matter interactions.