Parametrically induced readout of a superconducting qubit

ORAL

Abstract

One of the basic operations of quantum information is to non-destructively identify the state of a quantum system with high fidelity and within a time that is short compared to its natural decay. In circuit quantum electro-dynamics, this goal is achieved by the dispersive readout scheme, in which the frequency of an ancillary cavity is pulled by an amount depending on the qubit state. Despite its successes, this scheme suffers from the Purcell limit set on the decay time, and from the dephasing induced by spurious photons in the readout cavity. We address these shortcomings with a parametrically driven 3rd order interaction between the qubit excitation number and the cavity coherent state displacement. This interaction can also be described as a so-called “longitudinal” coupling between the qubit z operator and the readout cavity field amplitude, and it differs markedly from the usual "transversal" Jaynes-Cummings coupling between the qubit x operator and the field amplitude. This interaction can be tuned in-situ, and can be turned off altogether. The presentation will report experimental progress towards the realization of this scheme.

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Presenters

  • Steven Touzard

    Applied Physics, Yale University, Department of Applied Physics, Yale Univ, Yale Univ

Authors

  • Steven Touzard

    Applied Physics, Yale University, Department of Applied Physics, Yale Univ, Yale Univ

  • Angela Kou

    Applied Physics, Yale University, Yale Univ

  • Alexander Grimm

    PHELIQS, CEA Grenoble, Applied Physics, Yale University, Department of Applied Physics, Yale Univ, Yale Univ

  • Kevin Chou

    Applied Physics, Yale University, Physics and Applied Physics, Yale University, Dept. of Applied Physics, Yale University, Yale University, Yale Univ

  • Katrina Sliwa

    Yale Univ

  • Uri Vool

    Physics, Harvard University, Applied Physics, Yale University, Yale Univ

  • Shyam Shankar

    Applied Physics, Yale University, Department of Applied Physics, Yale University, Department of Applied Physics, Yale Univ, Yale Univ

  • Luigi Frunzio

    Yale University, Applied Physics, Yale University, Physics and Applied Physics, Yale University, Applied Physics, Yale Univ, Dept. of Applied Physics, Yale University, Department of Applied Physics, Yale Univ, Yale Univ, Departments of Applied Physics and Physics, Yale University

  • Michel Devoret

    Yale University, Applied Physics, Yale University, Department of Applied Physics, Yale University, Applied Physics, Yale Univ, Physics and Applied Physics, Yale University, Yale Univ, Dept. of Applied Physics, Yale University, Department of Applied Physics, Yale Univ