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Stabilization and operation of a Kerr-cat qubit.

Invited

Abstract

Superpositions of two opposite-phase coherent states in an oscillator, so-called Schrödinger-cat states, can be used to encode a qubit protected against phase-flip errors. Such a protected “cat qubit” has the potential to significantly reduce the overhead associated with quantum error correction. However, the practical operation of a cat qubit faces several challenges: Its basis states are highly excited states of the oscillator and need to be stabilized in order to maintain the protection. At the same time, the system has to be compatible with fast gates on the encoded qubit and a quantum non-demolition (QND) readout of the encoded information.

In this talk, I will present our recent experimental results on the stabilization of an error-protected cat qubit through the interplay between Kerr nonlinearity and single-mode squeezing in a superconducting microwave resonator. Our experiment demonstrates a full set of single-qubit gates and QND-readout on timescales significantly shorter than the relevant decoherence times.

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Presenters

  • Alexander Grimm

    Yale University, Paul Scherrer Institute

Authors

  • Alexander Grimm

    Yale University, Paul Scherrer Institute

  • Nicholas Frattini

    Yale University

  • Shruti Puri

    Yale University, Yale Quantum Institute, Yale University, Department of Applied Physics, Yale University, Department of Applied Physics and Physics, Yale University

  • Shantanu O Mundhada

    Quantum Circuits Inc., Yale University, Yale University, QCI

  • Steven Touzard

    Natl University of Singapore, Department of physics, National University of Singapore, Yale University, Nat. Univ. of Singapore

  • Mazyar Mirrahimi

    INRIA Paris, Quantic team, Inria Paris, Yale University, INRIA Paris, QUANTIC team, INRIA

  • Steven Girvin

    Yale University, Yale Quantum Institute, Yale University

  • Shyam Shankar

    University of Texas at Austin, Yale University, Department of electrical and computer engineering, University of Austin, Yale University, Univ. of Texas at Austin

  • Michel Devoret

    Yale University, Applied Physics Department, Yale University, Yale, Department of Applied Physics and Physics, Yale University, Applied Physics, Yale University, Departments of Applied Physics and Physics, Yale University