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arXiv · 1112.0900

High-Fidelity Polarization Storage in a Gigahertz Bandwidth Quantum Memory

D. G. England·P. S. Michelberger·T. F. M. Champion·K. F. Reim·K. C. Lee·M. R. Sprague·X. -M. Jin·N. K. Langford·W. S. Kolthammer·J. Nunn·I. A. Walmsley
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Abstract

We demonstrate a dual-rail optical Raman memory inside a polarization interferometer; this enables us to store polarization-encoded information at GHz bandwidths in a room-temperature atomic ensemble. By performing full process tomography on the system we measure up to 97\pm1% process fidelity for the storage and retrieval process. At longer storage times, the process fidelity remains high, despite a loss of efficiency. The fidelity is 86\pm4% for 1.5 \mu s storage time, which is 5,000 times the pulse duration. Hence high fidelity is combined with a large time-bandwidth product. This high performance, with an experimentally simple setup, demonstrates the suitability of the Raman memory for integration into large-scale quantum networks.

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D. G. England, P. S. Michelberger, T. F. M. Champion, K. F. Reim, K. C. Lee, M. R. Sprague, X. -M. Jin, N. K. Langford, W. S. Kolthammer, J. Nunn, I. A. Walmsley. 2011-12-05. High-Fidelity Polarization Storage in a Gigahertz Bandwidth Quantum Memory. https://doi.org/10.1088/0953-4075/45/12/124008

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