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arXiv · 1301.6924

Single-photon-level optical storage in a solid-state spin-wave memory

N. Timoney·I. Usmani·P. Jobez·M. Afzelius·N. Gisin
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Abstract

A long-lived quantum memory is a firm requirement for implementing a quantum repeater scheme. Recent progress in solid-state rare-earth-ion-doped systems justifies their status as very strong candidates for such systems. Nonetheless an optical memory based on spin-wave storage at the single-photon-level has not been shown in such a system to date, which is crucial for achieving the long storage times required for quantum repeaters. In this letter we show that it is possible to execute a complete atomic frequency comb (AFC) scheme, including spin-wave storage, with weak coherent pulses of $\bar{n} = 2.5 \pm 0.6$ photons per pulse. We discuss in detail the experimental steps required to obtain this result and demonstrate the coherence of a stored time-bin pulse. We show a noise level of $(7.1 \pm 2.3)10^{-3}$ photons per mode during storage, this relatively low-noise level paves the way for future quantum optics experiments using spin-waves in rare-earth-doped crystals.

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N. Timoney, I. Usmani, P. Jobez, M. Afzelius, N. Gisin. 2013-01-29. Single-photon-level optical storage in a solid-state spin-wave memory. https://doi.org/10.1103/physreva.88.022324

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