Hardware-efficient Bell state preparation using Quantum Zeno Dynamics in superconducting circuits.

ORAL

Abstract

By preforming a continuous joint measurement on a two qubit system, we restrict the qubit evolution to a chosen subspace of the total Hilbert space. This extension of the quantum Zeno effect, called Quantum Zeno Dynamics, has already been explored in various physical systems such as superconducting cavities, single rydberg atoms, atomic ensembles and Bose–Einstein condensates. In this experiment, two superconducting qubits are strongly dispersively coupled to a high-Q cavity ($\chi\gg\kappa$) allowing for the doubly excited state $|11\rangle$ to be selectively monitored. The Quantum Zeno Dynamics in the complementary subspace enables us to coherently prepare a Bell state. As opposed to dissipation engineering schemes, we emphasize that our protocol is deterministic, does not rely direct coupling between qubits and functions only using single qubit controls and cavity readout. Such Quantum Zeno Dynamics can be generalized to larger Hilbert space enabling deterministic generation of many-body entangled states, and thus realizes a decoherence-free subspace allowing alternative noise-protection schemes.

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Authors

  • Emmanuel Flurin

    • Quantum Nanoelectronics Laboratory, Department of Physics, University of California, Berkeley CA 94720, USA
    • Department of Physics University of California, Berkeley
    • Quantum Nanoelectronics Laboratory,Department of Physics, University of California, Berkeley
    • Quantum Nanoelectronics Lab, Center for Quantum Coherent Sciences, UC Berkeley

  • Machiel Blok

    • Quantum Nanoelectronics Laboratory, Department of Physics, University of California, Berkeley CA 94720, USA.
    • Quantum Nanoelectronics Laboratory,Department of Physics, University of California, Berkeley

  • Shay Hacohen-Gourgy

    • University of California
    • Quantum Nanoelectronics Laboratory, Department of Physics, University of California, Berkeley, CA 94720, USA.
    • University of California, Berkeley
    • Quantum Nanoelectronics Laboratory, Department of Physics, University of California, Berkeley CA 94720, USA.
    • Quantum Nanoelectronics Laboratory,Department of Physics, University of California, Berkeley

  • Leigh Martin

    • Quantum Nanoelectronics Laboratory, Department of Physics, University of California, Berkeley, CA 94720, USA.
    • University of California, Berkeley
    • Quantum Nanoelectronics Laboratory,Department of Physics, University of California, Berkeley
    • Univ of California - Berkeley
    • Quantum Nanoelectronics Lab, Center for Quantum Coherent Sciences, UC Berkeley

  • William Livingston

    • Quantum Nanoelectronics Laboratory, Department of Physics, University of California, Berkeley CA 94720, USA
    • Quantum Nanoelectronics Laboratory, Department of Physics, University of California, Berkeley CA 94720, USA.
    • Quantum Nanoelectronics Laboratory,Department of Physics, University of California, Berkeley
    • Quantum Nanoelectronics Lab, Center for Quantum Coherent Sciences, UC Berkeley

  • Allison Dove

    • Quantum Nanoelectronics Laboratory, Department of Physics, University of California, Berkeley CA 94720, USA
    • Quantum Nanoelectronics Laboratory, Department of Physics, University of California, Berkeley CA 94720, USA.
    • Quantum Nanoelectronics Laboratory,Department of Physics, University of California, Berkeley

  • Irfan Siddiqi

    • Quantum Nanoelectronics Laboratory, Department of Physics, University of California, Berkeley CA 94720, USA
    • Quantum Nanoelectronics Laboratory, Department of Physics, University of California, Berkeley, CA 94720, USA.
    • Quantum Nanoelectronics Laboratory, Department of Physics, University of California, Berkeley CA 94720, USA.
    • University of California, Berkeley
    • Quantum Nanoelectronics Laboratory, Department of Physics, University of California, Berkeley, California 94720, USA.
    • Quantum Nanoelectronics Laboratory
    • Quantum Nanoelectronics Laboratory,Department of Physics, University of California, Berkeley
    • Quantum Nanoelectronics Lab, Center for Quantum Coherent Sciences, UC Berkeley