We theoretically study specific schemes for performing a fundamental two-qubit quantum gate via controlled atomic collisions by switching microscopic potentials. In particular we calculate the fidelity of a gate operation for a configuration where a potential barrier between two atoms is instantaneously removed and restored after a certain time. Possible implementations could be based on microtraps created by magnetic and electric fields, or potentials induced by laser light.
@article{arxiv.quant-ph/9905013,
title = {Quantum gates with neutral atoms: Controlling collisional interactions in time dependent traps},
author = {T. Calarco and E. A. Hinds and D. Jaksch and J. Schmiedmayer and J. I. Cirac and P. Zoller},
journal= {arXiv preprint arXiv:quant-ph/9905013},
year = {2009}
}