Cryogenic Digital Readout of Superconducting Qubits

ORAL

Abstract

We present schemes for interfacing the result of superconducting qubit measurements with Single-Flux-Quantum (SFQ) logic, a superconducting cryogenic digital logic family. Using a Josephson Photomultiplier (JPM), we are able to read out a superconducting qubit coupled to a cavity by mapping qubit states onto cavity photon occupation, then mapping the cavity photon occupation onto different classical circulating current states of the JPM. This scheme provides fast, high fidelity readout at the same temperature stage as the qubit device without the need for cryogenic isolators or amplifiers. The results of this readout can then be encoded into SFQ logic by coupling the JPM to an underdamped Josephson Transmission Line (JTL) circuit. Simulations of this protocol, as well as recent JPM measurement results are discussed.

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Presenters

  • Caleb Howington

    Physics, Syracuse University, Physics, Syracuse Univ, Syracuse Univ, Syracuse University

Authors

  • Caleb Howington

    Physics, Syracuse University, Physics, Syracuse Univ, Syracuse Univ, Syracuse University

  • Alexander Opremcak

    Univ of Wisconsin, Madison, Physics, University of Wisconsin Madison, University of Wisconsin-Madison

  • Ivan Pechenezhskiy

    Univ of Wisconsin, Madison, University of Maryland, University of Maryland, College Park, Physics, University of Wisconsin Madison

  • Maxim Vavilov

    Physics, University of Wisconsin-Madison, Department of Physics, University of Wisconsin-Madison, Univ of Wisconsin, Madison, University of Wisconsin-Madison, Physics, University of Wisconsin Madison

  • Robert McDermott

    Univ of Wisconsin, Madison, Physics, University of Wisconsin - Madison, Physics, University of Wisconsin-Madison, Physics, Univ of Wisconsin-Madison, Physics, University of Wisconsin Madison, University of Wisconsin-Madison

  • Britton Plourde

    Syracuse Univ, Physics, Syracuse Univ, Syracuse University, Physics, Syracuse University