title: Single-step implementation of universal quantum gates.
abstract: We construct optimized implementations of the controlled-NOT and other universal two-qubit gates that, unlike many of the previously proposed protocols, are carried out in a single step. The new protocols require tunable interqubit couplings but, in return, show a significant improvement in the quality of gate operations. We make specific predictions for coupled Josephson junction qubits and compare them with the results of recent experiments.
authors.affiliation: Department of Physics and Astronomy, University of North Carolina, Chapel Hill, North Carolina 27599, USA.
authors.forename: I A
authors.initials: IA
authors.lastname: Grigorenko
authors.forename: D V
authors.initials: DV
authors.lastname: Khveshchenko