title: Optimal multiqubit operations for Josephson charge qubits.
abstract: We introduce a method for finding the required control parameters for a quantum computer that yields the desired quantum algorithm without invoking elementary gates. We concentrate on the Josephson charge-qubit model, but the scenario is readily extended to other physical realizations. Our strategy is to numerically find any desired double- or triple-qubit gate. The motivation is the need to significantly accelerate quantum algorithms in order to fight decoherence.
authors.affiliation: Materials Physics Laboratory, Helsinki University of Technology, POB 2200 (Technical Physics), FIN-02015 HUT, Espoo, Finland. antti.niskanen@vtt.fi
authors.forename: Antti O
authors.initials: AO
authors.lastname: Niskanen
authors.forename: Juha J
authors.initials: JJ
authors.lastname: Vartiainen
authors.forename: Martti M
authors.initials: MM
authors.lastname: Salomaa