title: Quantum coherent tunable coupling of superconducting qubits.
abstract: To do large-scale quantum information processing, it is necessary to control the interactions between individual qubits while retaining quantum coherence. To this end, superconducting circuits allow for a high degree of flexibility. We report on the time-domain tunable coupling of optimally biased superconducting flux qubits. By modulating the nonlinear inductance of an additional coupling element, we parametrically induced a two-qubit transition that was otherwise forbidden. We observed an on/off coupling ratio of 19 and were able to demonstrate a simple quantum protocol.
authors.affiliation: CREST, Japan Science and Technology Institute, Kawaguchi, Saitama 332-0012, Japan.
authors.forename: A O
authors.initials: AO
authors.lastname: Niskanen
authors.forename: K
authors.initials: K
authors.lastname: Harrabi
authors.forename: F
authors.initials: F
authors.lastname: Yoshihara
authors.forename: Y
authors.initials: Y
authors.lastname: Nakamura
authors.forename: S
authors.initials: S
authors.lastname: Lloyd
authors.forename: J S
authors.initials: JS
authors.lastname: Tsai