Antiblockade in Rydberg excitation of an ultracold lattice gas

• Main Authors: Ates, Cenap, Pohl, Thomas, Pattard, Thomas, Rost, Jan M
• Format: Journal Article
• Language: English
• Published: 12-05-2006
• Subjects: Physics - Atomic Physics
• DOI: 10.48550/arxiv.physics/0605111

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.