title: Cavity-mediated entanglement generation via Landau-Zener interferometry.
abstract: We demonstrate quantum control and entanglement generation using a Landau-Zener beam splitter formed by coupling two transmon qubits to a superconducting cavity. Single passage through the cavity-mediated qubit-qubit avoided crossing provides a direct test of the Landau-Zener transition formula. Consecutive sweeps result in Landau-Zener-Stückelberg interference patterns, with a visibility that can be sensitively tuned by adjusting the level velocity through both the nonadiabatic and adiabatic regimes. Two-qubit state tomography indicates that a Bell state can be generated via a single passage, with a fidelity of 78% limited by qubit relaxation.
authors.affiliation: Department of Physics, Princeton University, Princeton, New Jersey 08544, USA.
authors.forename: C M
authors.initials: CM
authors.lastname: Quintana
authors.forename: K D
authors.initials: KD
authors.lastname: Petersson
authors.forename: L W
authors.initials: LW
authors.lastname: McFaul
authors.forename: S J
authors.initials: SJ
authors.lastname: Srinivasan
authors.forename: A A
authors.initials: AA
authors.lastname: Houck
authors.forename: J R
authors.initials: JR
authors.lastname: Petta