An ultra-high optical depth cold atomic ensemble for quantum memories
Ben M. Sparkes, J. Bernu, Mahdi Hosseini +6 more
Quantum memories for light lie at the heart of long-distance provably-secure communication. Demand for a functioning quantum memory, with high efficiency and coherence times approaching a millisecond, is therefore at a premium. Here we report on work towards this goal, with the development of a 87 Rb magneto-optical trap with a peak optical depth of 1000 for the D2 F = 2 → F ' = 3 transition using spatial and temporal dark spots. With this purpose-built cold atomic ensemble we implemented the gradient echo memory (GEM) scheme on the D1 line. Our data shows a memory efficiency of 80 ± 2% and coherence times up to 195 μ s.
Journal of Physics Conference Series•Dec 6, 2013•9 citations