2015/01/31 by Pierre Jobez, Cyril Laplane, Nuala Timoney +4
Physics and Astronomy · #quant-ph
paper · pdf · doi:10.1103/physrevlett.114.230502
published as Phys. Rev. Lett. 114, 230502 (2015) · 5 pages, 2 figures, 1 table
arxiv created 2015/06/17 · arxiv updated 2015/06/18
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.