1107.4394 (F. Ciccarello et al.)

Quasideterministic realization of a universal quantum gate in a single
scattering process    [PDF]

F. Ciccarello, D. E. Browne, L. C. Kwek, H. Schomerus, M. Zarcone, S. Bose

We show that a flying particle, such as an electron or a photon, scattering along a one-dimensional waveguide from a pair of static spin-1/2 centers, such as quantum dots, can implement a CZ gate (universal for quantum computation) between them. This occurs quasi-deterministically in a single scattering event, hence with no need for any post-selection or iteration, {and} without demanding the flying particle to bear any internal spin. We show that an easily matched hard-wall boundary condition along with the elastic nature of the process are key to such performances.

View original: http://arxiv.org/abs/1107.4394