Quantum nondemolition readout using a Josephson bifurcation amplifier
Nicolas Boulant, Grégoire Ithier, P. J. Meeson, F. Nguyen, D. Vion, Daniel Esteve, Irfan A. Siddiqi, Rajamani Vijay, Chad T. Rigetti, F. Pierre, Michel Devoret · Physical Review B · 2007
We report an experiment on the determination of the quantum nondemolition (QND) nature of a readout scheme of a quantum electrical circuit. The circuit is a superconducting quantum bit measured by microwave reflectometry using a Josephson bifurcation amplifier. We perform a series of two subsequent measurements, record their values and correlation, and quantify the QND character of this readout.