title: Superconducting resonators as beam splitters for linear-optics quantum computation.
abstract: We propose and analyze a technique for producing a beam-splitting quantum gate between two modes of a ring-resonator superconducting cavity. The cavity has two integrated superconducting quantum interference devices (SQUIDs) that are modulated by applying an external magnetic field. The gate is accomplished by applying a radio frequency pulse to one of the SQUIDs at the difference of the two mode frequencies. Departures from perfect beam splitting only arise from corrections to the rotating wave approximation; an exact calculation gives a fidelity of >0.9992. Our construction completes the toolkit for linear-optics quantum computing in circuit quantum electrodynamics.
authors.affiliation: Department of Physics, University of Konstanz, D-78457 Konstanz, Germany.
authors.forename: Luca
authors.initials: L
authors.lastname: Chirolli
authors.forename: Guido
authors.initials: G
authors.lastname: Burkard
authors.forename: Shwetank
authors.initials: S
authors.lastname: Kumar
authors.forename: David P
authors.initials: DP
authors.lastname: Divincenzo