High fidelity all-microwave controlled-phase gate for superconducting qubits by cavity vacuum displacement

ORAL

Abstract

We demonstrate a new all-microwave controlled phase entangling gate for the superconducting qubits in the three-dimensional circuit QED (3D cQED) architecture. The gate exploits the strong coupling between qubits and a cavity, wherein the cavity frequency dispersively shifts depending on the qubit register state. We off-resonantly displace the cavity vacuum state; each computational state evolves a different phase due to the dispersive coupling, yielding a conditional phase. While designed to exploit the advantages of the 3D cQED architecture, the gate requires only dispersive coupling, making the gate applicable to a wide variety of superconducting qubit architectures. We demonstrate 98\% gate fidelity evaluated by quantum process tomography, and will discuss how appropriate choices of system parameters could increase this number and how we could minimize the gate infidelity due to measurement induced dephasing and non-adiabatic gate procedure.

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Authors

  • Hanhee Paik

    Raytheon BBN Technologies and Yale University, Department of Physics and Applied Physics, Yale University

  • D. Zhou

    Yale University

  • Matthew Reed

    Yale University, Yale University Dept. of Applied Physics

  • Gerhard Kirchmair

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

  • Luigi Frunzio

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

  • Steven Girvin

    Yale University, Yale University Dept. of Physics

  • Robert Schoelkopf

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