Photon Blockade in Two-Emitter-Cavity Systems

TL;DR

This paper explores photon blockade mechanisms in a two-emitter-cavity system, revealing three distinct types—polaritonic, subradiant, and unconventional—with implications for robust single-photon sources in solid-state quantum optics.

Contribution

It introduces and analyzes three photon blockade mechanisms in a two-emitter-cavity system, including a novel subradiant effect due to emitter inhomogeneity.

Findings

Polaritonic PB occurs at polariton frequencies in multi-emitter systems.

Subradiant PB offers a more robust single-photon emission.

Unconventional PB suppresses two-photon correlations and enhances three-photon correlations.

Abstract

The photon blockade (PB) effect in emitter-cavity systems depends on the anharmonicity of the ladder of dressed energy eigenstates. The recent developments in color center photonics are leading toward experimental demonstrations of multi-emitter-cavity solid-state systems with an expanded set of energy levels compared to the traditionally studied single-emitter systems. We focus on the case of N = 2 nonidentical quasi-atoms strongly coupled to a nanocavity in the bad cavity regime (with parameters within reach of the color center systems), and discover three PB mechanisms: polaritonic, subradiant and unconventional. The polaritonic PB, which is the conventional mechanism studied in single-emitter-cavity systems, also occurs at the polariton frequencies in multi-emitter systems. The subradiant PB is a new interference effect owing to the inhomogeneous broadening of the emitters which results in a purer and a more robust single photon emission than the polaritonic PB. The unconventional PB in the modeled system corresponds to the suppression of the single- and two-photon correlation statistics and the enhancement of the three-photon correlation statistic. Using the effective Hamiltonian approach, we unravel the origin and the time-domain evolution of these phenomena.