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arXiv · 2510.26870

Single-Photon-Level Atomic Frequency Comb Storage in Room Temperature Alkali Vapour

Zakary Schofield·Vanderli Laurindo Jr·Ori Ezrah Mor·Patrick M. Ledingham
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Abstract

We have demonstrated the coherent storage and retrieval of single-photon-level light using the atomic frequency comb protocol in a room temperature rubidium vapour. Velocity-selective optical pumping is used to prepare the comb within the $F=2$ hyperfine ground state of rubidium, with the spacing between peaks coinciding with half the $F = 2 - F =3$ hyperfine splitting of the $5^2$P$_{3/2}$ excited state. Weak coherent states of average photon number $\mu_\mathrm{in} = 0.083(5)$ are stored with pre-programmed recall time of $7.5\,$ns with an efficiency of $\eta_{\textrm{AFC}} = 6.59(5)\,\%$, while two temporally distinct modes have been stored and recalled with $\eta_{\textrm{AFC}} = 2.6(1)\,\%$, allowing for time-bin qubit storage. Finally, the efficiency is observed to be independent of the input pulse polarisation, paving the way for polarisation qubit storage.

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Zakary Schofield, Vanderli Laurindo Jr, Ori Ezrah Mor, Patrick M. Ledingham. 2025-10-30. Single-Photon-Level Atomic Frequency Comb Storage in Room Temperature Alkali Vapour. https://doi.org/10.1103/y4kq-ckhq

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