Scalable Neutral Atom Quantum Computer with Interaction on Demand:   Proposal for Selective Application of Two-Qubit Gate
  We propose a scalable neutral atom quantum computer with an on-demand interaction through a selective two-qubit gate operation. Atoms are trapped by a lattice of near field Fresnel diffraction lights so that each trap captures a single atom. One-qubit gate operation is implemented by a gate control laser beam which is applied to an individual atom. Two-qubit gate operation between an arbitrary pair of atoms is implemented by sending these atoms to a state-dependent optical lattice and making them collide so that a particular two-qubit state acquires a dynamical phase. We give numerical evaluations corresponding to these processes, from which we estimate the upper bound of a two-qubit gate operation time and corresponding gate fidelity. Our proposal is feasible within currently available technology developed in cold atom gas, MEMS, nanolithography, and various areas in optics. 
Elham Hosseini Lapasar, Kenichi Kasamatsu, Yasushi Kondo, Mikio   Nakahara, Tetsuo Ohmi
quant-ph cond-mat.quant-gas