Implementing phase gates with cold collisions in an optical lattice

Jyrki Piilo

Kirstine Berg‐Sørensen

Biophysics

T. Eichler, T. Mukai, A. Kasper +1 more

Dieter Jaksch, Hans J. Briegel, J. I. Cirac +2 more

We show that by using cold controlled collisions between two atoms one can achieve conditional dynamics in moving trap potentials. We discuss implementing two qubit quantum gates and efficient creation of highly entangled states of many atoms in optical lattices.

Andrew J. Kerman

M. A. Duenas, Ángela M. Guzmán

We study a dipole-dipdole collision between two atoms confined in adjacent minima of the two sublattices of an optical lattice with polarization gradient. A qubit consists of the two lowest atomic vibrational states of the optical lattice potential. The inter-atomic distance is changed adiabatically by rotating the polarization of the lasers that originate the optical lattice. In an elastic collision the two-qubit quantum states undergo controllable phase shifts that allow for the implementation of quantum gates. We obtain the truth-table for a quantum logic phase gate and calculate probability losses caused by the non-hermitian effective dipole-dipole interaction Hamiltonian.