Antiblockade in Rydberg excitation of an ultracold lattice gas

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.Comment: 4 pages, 6 figure

Some New Symmetric Identities for the q-Zeta Type Functions

The main object of this paper is to obtain several symmetric properties of the q-Zeta type functions. As applications of these properties, we give some new interesting identities for the modified q-Genocchi polynomials. Finally, our applications are shown to lead to a number of interesting results which we state in the present paper.Comment: 8 pages; submitte