Characterization and mitigation of noise and crosstalk in a five-qutrit transmon processor

ORAL

Abstract

The multi-level structure of the transmon circuit makes it an attractive choice for implementing multi-valued quantum logic, i.e. qudit-based protocols with d > 2. To date, while transmon levels outside of the qubit computational subspace have been used for control and sensing, experimental implementation of a quantum algorithm using multi-level transmons has not been demonstrated. Specifically, we address practical issues which arise when running a multi-qutrit algorithm. These include classical microwave crosstalk between the individual transmon control lines; an always-on ZZ interaction due to fixed off-resonant coupling between neighboring qutrits; conditionality of single-qutrit pulses due to the cross-resonance effect; and challenges due to the sensitivity of higher transmon levels to charge noise. For each of these issues, we present methods of characterization and mitigation, demonstrating their efficacy on our hardware and the future design choices they inform.

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Presenters

  • Vinay Ramasesh

    Physics, Univ of California – Berkeley, University of California, Berkeley

Authors

  • Vinay Ramasesh

    Physics, Univ of California – Berkeley, University of California, Berkeley

  • Machiel Blok

    Physics, Univ of California – Berkeley, Univ of California - Berkeley, University of California, Berkeley

  • Kevin P. O'Brien

    Department of Electrical Engineering and Computer Science, Massachusetts Institute of Technology, Electrical Engineering and Computer Science, Research Laboratory of Electronics, Massachusetts Institute of Technology, Department of Electrical Engineering and Computer Science, Massachusetts Institute of Technology, Cambridge, Massachusetts 02139, USA, University of California, Berkeley

  • Dar Dahlen

    Physics, Univ of California – Berkeley, University of California, Berkeley

  • John Mark Kreikebaum

    Univ of California – Berkeley, University of California, Berkeley

  • Irfan Siddiqi

    University of California, Berkeley, Physics, University of California, Berkeley, Univ of California – Berkeley, Univ of California - Berkeley, Physics, Univ of California – Berkeley