Rydberg assisted light shift imbalance induced blockade in an atomic ensemble

Abstract

Previously, we had proposed the technique of light shift imbalance induced blockade which leads to a condition where a collection of non-interacting atoms under laser excitation remains combined to a superposition of the ground and the first excited states, thus realizing a collective state quantum bit which in turn can be used to realize a quantum computer. In this paper, we show first that the light shift imbalance by itself is actually not enough to produce such a blockade, and explain the reason why the limitation of our previous analysis had reached this constraint. We then show that by introducing Rydberg interaction, it is possible to achieve such a blockade for a wide range of parameters. Analytic arguments used to establish these results are confirmed by numerical simulations. The fidelity of coupled quantum gates based on such collective state qubits is highly insensitive to the exact number of atoms in the ensemble. As such, this approach may prove to be viable for scalable quantum computing based on neutral atoms.

12 pages with 12 figures

References in corpus (5)

• Cooperative atom-light interaction in a blockaded Rydberg ensemble
• Evidence for coherent collective Rydberg excitation in the strong blockade regime
• Quantum gates and multi-particle entanglement by Rydberg excitation blockade and adiabatic passage
• Quantum computing with collective ensembles of multi-level systems
• Light-Shift Imbalance Induced Blockade of Collective Excitations Beyond the Lowest Order