An ultra-high optical depth cold atomic ensemble for quantum memories

21st International Conference on Laser Spectroscopy

Sparkes, B.M.^1 ; Bernu, J.^1 ; Hosseini, M.^1 ; Geng, J.^1,2 ; Glorieux, Q.^1,3 ; Altin, P.A.^4 ; Lam, P.K.^1 ; Robins, N.P.^4 ; Buchler, B.C.^1

Department of Quantum Science, Research School of Physics and Engineering, Australian National University, Canberra, ACT 0200, Australia^1

Quantum Institute for Light and Atoms, Department of Physics, East China Normal University, Shanghai 200062, China^2

Joint Quantum Institute, University of Maryland, College Park, MD 20742, United States^3

Quantum Sensors Lab, Department of Quantum Science, Australian National University, Canberra, ACT 0200, Australia^4

关键词: Atomic ensemble;    Coherence time;    Gradient echo;    High-efficiency;    Magnetooptical traps;    Memory efficiency;    Optical depth;    Quantum memory;   

Others  :  https://iopscience.iop.org/article/10.1088/1742-6596/467/1/012009/pdf
DOI  :  10.1088/1742-6596/467/1/012009

来源: IOP

【 摘 要 】

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 a87Rb 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 μs.