title: Nondestructive readout for a superconducting flux qubit.
abstract: We present a new readout method for a superconducting flux qubit, based on the measurement of the Josephson inductance of a superconducting quantum interference device that is inductively coupled to the qubit. The intrinsic flux detection efficiency and backaction are suitable for a fast and nondestructive determination of the quantum state of the qubit, as needed for readout of multiple qubits in a quantum computer. We performed spectroscopy of a flux qubit and we measured relaxation times of the order of 80 micros.
authors.affiliation: Kavli Institute of Nanoscience, Delft University of Technology, PO Box 5046, 2600 GA Delft, The Netherlands.
authors.forename: A
authors.initials: A
authors.lastname: Lupaşcu
authors.forename: C J M
authors.initials: CJ
authors.lastname: Verwijs
authors.forename: R N
authors.initials: RN
authors.lastname: Schouten
authors.forename: C J P M
authors.initials: CJ
authors.lastname: Harmans
authors.forename: J E
authors.initials: JE
authors.lastname: Mooij