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.
@article{arxiv.2212.06307,
title = {Non-Hermitian Anharmonicity Induces Single-Photon Emission},
author = {Anael Ben-Asher and Antonio I. Fernández-Domínguez and Johannes Feist},
journal= {arXiv preprint arXiv:2212.06307},
year = {2024}
}