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arXiv · 1501.03981

Coherent spin control at the quantum level in an ensemble-based optical memory

Pierre Jobez·Cyril Laplane·Nuala Timoney·Nicolas Gisin·Alban Ferrier·Philippe Goldner·Mikael Afzelius
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Abstract

Long-lived quantum memories are essential components of a long-standing goal of remote distribution of entanglement in quantum networks. These can be realized by storing the quantum states of light as single-spin excitations in atomic ensembles. However, spin states are often subjected to different dephasing processes that limit the storage time, which in principle could be overcome using spin-echo techniques. Theoretical studies have suggested this to be challenging due to unavoidable spontaneous emission noise in ensemble-based quantum memories. Here we demonstrate spin-echo manipulation of a mean spin excitation of 1 in a large solid-state ensemble, generated through storage of a weak optical pulse. After a storage time of about 1 ms we optically read out the spin excitation with a high signal-to-noise ratio. Our results pave the way for long-duration optical quantum storage using spin-echo techniques for any ensemble-based memory.

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Pierre Jobez, Cyril Laplane, Nuala Timoney, Nicolas Gisin, Alban Ferrier, Philippe Goldner, Mikael Afzelius. 2015-06-17. Coherent spin control at the quantum level in an ensemble-based optical memory. https://doi.org/10.1103/physrevlett.114.230502

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