Gradient echo memory in an ultra-high optical depth cold atomic ensemble

B M Sparkes; J Bernu; M Hosseini; J Geng; Q Glorieux; P A Altin; P K Lam; N P Robins; B C Buchler

doi:10.1088/1367-2630/15/8/085027

New Journal of Physics (Jan 2013)

Gradient echo memory in an ultra-high optical depth cold atomic ensemble

B M Sparkes,
J Bernu,
M Hosseini,
J Geng,
Q Glorieux,
P A Altin,
P K Lam,
N P Robins,
B C Buchler

Affiliations

B M Sparkes: Centre for Quantum Computation and Communication Technology, Department of Quantum Science, Research School of Physics and Engineering, The Australian National University , Canberra, ACT 0200, Australia
J Bernu: Centre for Quantum Computation and Communication Technology, Department of Quantum Science, Research School of Physics and Engineering, The Australian National University , Canberra, ACT 0200, Australia
M Hosseini: Centre for Quantum Computation and Communication Technology, Department of Quantum Science, Research School of Physics and Engineering, The Australian National University , Canberra, ACT 0200, Australia
J Geng: Centre for Quantum Computation and Communication Technology, Department of Quantum Science, Research School of Physics and Engineering, The Australian National University , Canberra, ACT 0200, Australia; Quantum Institute for Light and Atoms, Department of Physics, East China Normal University , Shanghai 200062, People's Republic of China
Q Glorieux: Centre for Quantum Computation and Communication Technology, Department of Quantum Science, Research School of Physics and Engineering, The Australian National University , Canberra, ACT 0200, Australia; Joint Quantum Institute, University of Maryland , College Park, MD 20742, USA
P A Altin: Quantum Sensors Lab, Department of Quantum Science, Australian National University , Canberra, ACT 0200, Australia
P K Lam: Centre for Quantum Computation and Communication Technology, Department of Quantum Science, Research School of Physics and Engineering, The Australian National University , Canberra, ACT 0200, Australia
N P Robins: Quantum Sensors Lab, Department of Quantum Science, Australian National University , Canberra, ACT 0200, Australia
B C Buchler: Centre for Quantum Computation and Communication Technology, Department of Quantum Science, Research School of Physics and Engineering, The Australian National University , Canberra, ACT 0200, Australia

DOI: https://doi.org/10.1088/1367-2630/15/8/085027
Journal volume & issue: Vol. 15, no. 8
p. 085027

Abstract

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Quantum memories are an integral component of quantum repeaters—devices that will allow the extension of quantum key distribution to communication ranges beyond that permissible by passive transmission. A quantum memory for this application needs to be highly efficient and have coherence times approaching a millisecond. 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, which is a factor of four greater than previous GEM experiments implemented in warm vapour cells.

Published in New Journal of Physics

ISSN: 1367-2630 (Online)
Publisher: IOP Publishing
Country of publisher: United Kingdom
LCC subjects: Science: Physics
Website: https://iopscience.iop.org/journal/1367-2630

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