Tunable entanglement, antibunching, and saturation effects in dipole blockade

We report a model that makes it possible to analyze quantitatively the dipole blockade effect on the dynamical evolution of a two two-level atom system driven by an external laser field. The multiple excitations of the atomic sample are taken into account. We find very large concurrence in the dipole blockade regime. We further find that entanglement can be tuned by changing the intensity of the exciting laser. We also report a way to lift the dipole blockade paving the way to manipulate, in a controllable way, the blockade effects. We finally report how a continuous monitoring of the dipole blockade will be possible using photon-photon correlations of the scattered light in a regime where the spontaneous emission will dominate dissipation in the sample. ©2010 The American Physical Society