Entangling dipole-dipole interactions for quantum logic with neutral atoms- art. no. 062309

We study a means of creating multiparticle entanglement of neutral atoms us ing pairwise controlled dipole-dipole interactions. For tightly trapped ato ms the dipolar interaction energy can be much larger than the photon scatte ring rate and substantial coherent evolution of the two-atom state can be a chieved before decoherence occurs. Excitation of the dipoles can be made co nditional on the atomic states, allowing for deterministic generation of en tanglement. We derive selection rules and a figure of merit for the dipole- dipole interaction matrix elements, for alkali atoms with hyperfine structu re and trapped in localized center of mass states. Different protocols an p resented for implementing two-qubit quantum logic gales such as the control led-phase and swap gates. We analyze the error probability of our gate desi gns, finite due to decoherence from cooperative spontaneous emission and co herent couplings outside the logical basis. Outlines for extending our mode l to include the full molecular interactions potentials are discussed.