title: Partial-measurement backaction and nonclassical weak values in a superconducting circuit.
abstract: We realize indirect partial measurement of a transmon qubit in circuit quantum electrodynamics by interaction with an ancilla qubit and projective ancilla measurement with a dedicated readout resonator. Accurate control of the interaction and ancilla measurement basis allows tailoring the measurement strength and operator. The tradeoff between measurement strength and qubit backaction is characterized through the distortion of a qubit Rabi oscillation imposed by ancilla measurement in different bases. Combining partial and projective qubit measurements, we provide the solid-state demonstration of the correspondence between a nonclassical weak value and the violation of a Leggett-Garg inequality.
authors.affiliation: Kavli Institute of Nanoscience, Delft University of Technology, P.O. Box 5046, 2600 GA Delft, The Netherlands.
authors.forename: J P
authors.initials: JP
authors.lastname: Groen
authors.forename: D
authors.initials: D
authors.lastname: Ristè
authors.forename: L
authors.initials: L
authors.lastname: Tornberg
authors.forename: J
authors.initials: J
authors.lastname: Cramer
authors.forename: P C
authors.initials: PC
authors.lastname: de Groot
authors.forename: T
authors.initials: T
authors.lastname: Picot
authors.forename: G
authors.initials: G
authors.lastname: Johansson
authors.forename: L
authors.initials: L
authors.lastname: DiCarlo