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Antiblockade in Rydberg excitation of an ultracold lattice gas

Cenap Ates·Thomas Pohl·Thomas Pattard·Jan M. Rost
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Abstract

It is shown that the two-step excitation scheme typically used to create an ultracold Rydberg gas can be described with an effective two-level rate equation, greatly reducing the complexity of the optical Bloch equations. This allows us to solve the many-body problem of interacting cold atoms with a Monte Carlo technique. Our results reproduce the Rydberg blockade effect. However, we demonstrate that an Autler-Townes double peak structure in the two-step excitation scheme, which occurs for moderate pulse lengths as used in the experiment, can give rise to an antiblockade effect. It is observable in a lattice gas with regularly spaced atoms. Since the antiblockade effect is robust against a large number of lattice defects it should be experimentally realizable with an optical lattice created by CO$_{2}$ lasers.

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Cenap Ates, Thomas Pohl, Thomas Pattard, Jan M. Rost. 2006-05-12. Antiblockade in Rydberg excitation of an ultracold lattice gas. https://doi.org/10.1103/physrevlett.98.023002

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