Flux qubit readout at the degeneracy point

ORAL

Abstract


The role of measurement is crucial for the realization of a real world quantum computer. A promising candidate to deliver a platform to perform quantum algorithms are superconducting qubits, one of which is the flux qubit. Due to their natural coupling properties, flux qubits are especially interesting for the implementation of quantum annealer.
The most robust point of flux qubits against environmental effects that decohere the qubit (e.g. 1/f noise) is the so called degeneracy point. Because of this property one wants to operate at this specific point. However, performing a readout that conserves the measured observable (QND) is difficult here.
In this work we present an indirect measurement scheme for flux qubits which works at arbitrary bias points, most interesting also at the degeneracy point. We show that our protocol is able to reach high fidelities while acting QND on the measured qubit.

*This research is funded by the Intelligence Advanced Research Activity (IARPA). The views and conclusions contained in this presentation are those of the authors and should not be interpreted as necessarily representing the official policies or endorsements, either expressed or implied, of IARPA or the U.S. Governement.

–

Presenters

  • Marius Schöndorf

    • Saarland University

Authors

  • Marius Schöndorf

    • Saarland University

  • Adrian Lupascu

    • University of Waterloo
    • Institute for Quantum Computing, Department of Physics and Astronomy, and Waterloo Institute for Nanotechnology, University of Waterloo
    • Physics and Astronomy, Institute for Quantum Computing, Waterloo Institute for Nanotechnology, University of Waterloo

  • Frank K Wilhelm

    • Theoretische Physik, Saarland University
    • Saarland University
    • Univ des Saarlandes