Emergent Non-Markovian Dynamics in Logical Qubit Systems

ORAL

Abstract

Simulations of error-corrected logical qubits have demonstrated that logical qubit dynamics can exhibit non-Markovian behavior, even when the underlying physical noise is Markovian. Such non-Markovian dynamics present challenges to holistic logical qubit characterization and can also non-trivially degrade the performance of operational tasks performed on error-corrected quantum computers. To understand this emergent non-Markovianty, we construct a method for mapping arbitrary Markovian physical qubit dynamics to logical qubit dynamics. Examining a particular form of Markovianity relevant to gates, we provide illustrative examples in small quantum codes to explain these non-Markovian phenomena. Finally, we use measures of non-Markovianity to determine sufficient conditions for the use of gate-based characterization techniques (such as gate set tomography) in early fault-tolerant quantum devices.

*Sandia National Laboratories is a multimission laboratory managed and operated by National Technology & Engineering Solutions of Sandia, LLC, a wholly owned subsidiary of Honeywell International Inc., for the U.S. Department of Energy’s National Nuclear Security Administration under contract DENA0003525.

Presenters

  • Jalan A Ziyad

    • University of New Mexico

Authors

  • Jalan A Ziyad

    • University of New Mexico
  • Robin Blume-Kohout

    • Sandia National Laboratories
  • Tzvetan S Metodi

    • Sandia National Laboratories
  • Kenneth M Rudinger

    • Sandia National Laboratories