Non-Hermitian Anharmonicity Induces Single-Photon Emission

TL;DR

This paper introduces a new mechanism for single-photon emission based on non-Hermitian anharmonicity in losses, demonstrated in hybrid cavity-emitter systems, enabling high-purity, high-rate photon sources for quantum technologies.

Contribution

It presents the novel concept of non-Hermitian anharmonicity as a means to achieve single-photon emission, expanding the design principles for quantum light sources.

Findings

High-purity single-photon emission achieved

Effective in hybrid metallodielectric cavity systems

Operates at high repetition rates

Abstract

Single-photon sources are in high demand for quantum information applications. A paradigmatic way to achieve single-photon emission is through anharmonicity in the energy levels, such that the absorption of a single photon from a coherent drive shifts the system out of resonance and prevents absorption of a second one. We identify a novel mechanism for single-photon emission through non-Hermitian anharmonicity, i.e., anharmonicity in the losses instead of in the energy levels. We demonstrate the mechanism in two types of systems, including a feasible setup consisting of a hybrid metallodielectric cavity weakly coupled to a two-level emitter, and show that it induces high-purity single-photon emission at high repetition rates.