Room-temperature single-photon source with near-millisecond built-in memory

Abstract

Non-classical photon sources are a crucial resource for distributed quantum networks. Photons generated from matter systems with memory capability are particularly promising, as they can be integrated into a network where each source is used on-demand. Among all kinds of solid state and atomic quantum memories, room-temperature atomic vapours are especially attractive due to their robustness and potential scalability. To-date room-temperature photon sources have been limited either in their memory time or the purity of the photonic state. Here we demonstrate a single-photon source based on room-temperature memory. Following heralded loading of the memory, a single photon is retrieved from it after a variable storage time. The single-photon character of the retrieved field is validated by the strong suppression of the two-photon component with antibunching as low as $${g}_{{\rm{RR| W = 1}}}^{(2)}=0.20\pm 0.07$$ g RR∣W=1 ( 2 ) = 0.20 ± 0.07 . Non-classical correlations between the heralding and the retrieved photons are maintained for up to $${\tau }_{{\rm{NC}}}^{{\mathcal{R}}}=(0.68\pm 0.08)\ {\rm{ms}}$$ τ NC R = ( 0.68 ± 0.08 ) ms , more than two orders of magnitude longer than previously demonstrated with other room-temperature systems. Correlations sufficient for violating Bell inequalities exist for up to τBI = (0.15 ± 0.03) ms.

Field-deployable Quantum Memory for Quantum Networking

“…Second, we consider the storage efficiency η. It has been proposed [82] and demonstrated [83][84][85][86] that an optical cavity outside of an atomic vapor could enhance the light-matter interaction while, at the same time, suppressing the noise generation, which yields high η without sacrificing F. Third, there are methods to further suppress the noise to achieve even higher fidelity, such as the judicious use of "magic detuning" [85].…”

Proposal for room-temperature quantum repeaters with nitrogen-vacancy centers and optomechanics

“…Most current approaches to such quantum networks require either vacuum equipment and optical trapping or cryogenic cooling [7,[9][10][11][12][13][14][15][16], which adds significantly to the difficulty of scaling up such architectures. There is notable recent work towards quantum networks with room-temperature atomic ensembles [17][18][19][20][21], but it is also of interest to investigate solid-state approaches, which might ultimately be the most advantageous in terms of scalability.…”

Enhancing photon generation rate with broadband room-temperature quantum memory

“…Therefore, how to well preserve the collective excitation in presence of severe decoherence and extract signal photons from strong noise has been a long-standing challenge for making room-temperature memory-based photon source work in quantum regime. Recently, efforts have been made in implementing room-temperature single-photon sources with built-in memory 25 , and a further enhancement of photon generation, especially when the broadband feature allows operations at a high-data rate, will make it more appealing for real-life applications.…”