Cavity enhanced telecom heralded single photons for spin-wave solid state quantum memories

TL;DR

This paper presents a heralded single-photon source at telecom wavelengths compatible with solid-state quantum memories, demonstrating high efficiency, non-classical correlations, and potential for on-demand quantum memory applications.

Contribution

We developed a narrowband, telecom-compatible heralded single-photon source with high efficiency and demonstrated its suitability for solid-state quantum memories, advancing quantum communication technology.

Findings

Heralding efficiency of 28%

Generation rate over 2000 pairs/mW

Confirmed non-classical photon correlations

Abstract

We report on a source of heralded narrowband (3MHz) single photons compatible with solid-state spin-wave quantum memories based on praseodymium doped crystals. Widely non-degenerate narrow-band photon pairs are generated using cavity enhanced down conversion. One photon from the pair is at telecom wavelengths and serves as heralding signal, while the heralded single photon is at 606nm, resonant with an optical transition in Pr:YSO. The source offers a heralding efficiency of 28% and a generation rate exceeding 2000 pairs/mW in a single-mode. The single photon nature of the heralded field is confirmed by a direct antibunching measurement, with a measured antibunching parameter down to 0.010(4). Moreover, we investigate in detail photon cross- and autocorrelation functions proving non-classical correlations between the two photons. The results presented in this paper represent significant improvement over the state of the art and offer prospects for the demonstration of single photon spin-wave storage in an on-demand solid state quantum memory, heralded by a telecom photon.