Perfect single-photon sources

TL;DR

This paper introduces the concept of a gapped coherent state as a novel single-photon source that enforces a minimum time gap between photons, exploring its statistical properties and implications for perfect single-photon emission.

Contribution

The paper proposes a new theoretical model of a single-photon source with a minimum time gap between photons and analyzes its statistical properties.

Findings

The gapped coherent state exhibits counter-intuitive statistical features.

It provides a connection between continuous-wave and pulsed single-photon sources.

The model offers insights into what constitutes a perfect single-photon source.

Abstract

We introduce the "gapped coherent state" in the form of a single-photon source (SPS) that consists of uncorrelated photons as a background, except that we demand that no two photons can be closer in time than a time gap $t_\mathrm{G}$. While no obvious quantum mechanism is yet identified to produce exactly such a photon stream, a numerical simulation is easily achieved by first generating an uncorrelated (Poissonian) signal and then for each photon in the list, either adding such a time gap or removing all successive photons that are closer in time from any photon that is kept than $t_\mathrm{G}$. We study the statistical properties of such a hypothetical signal, which exhibits counter-intuitive features. This provides a neat and natural connection between continuous-wave (stationary) and pulsed single-photon sources, with also a bearing on what it means for such sources to be perfect in terms of single-photon emission.