Experimental Characterization of Crosstalk Errors with Simultaneous Gate Set Tomography

  1. Kenneth Rudinger,
  2. Craig W. Hogle,
  3. Ravi K. Naik,
  4. Akel Hashim,
  5. Daniel Lobser,
  6. David I. Santiago,
  7. Matthew D. Grace,
  8. Erik Nielsen,
  9. Timothy Proctor,
  10. Stefan Seritan,
  11. Susan M. Clark,
  12. Robin Blume-Kohout,
  13. Irfan Siddiqi,
  14. and Kevin C. Young
Crosstalk is a leading source of failure in multiqubit quantum information processors. It can arise from a wide range of disparate physical phenomena, and can introduce subtle correlations
in the errors experienced by a device. Several hardware characterization protocols are able to detect the presence of crosstalk, but few provide sufficient information to distinguish various crosstalk errors from one another. In this article we describe how gate set tomography, a protocol for detailed characterization of quantum operations, can be used to identify and characterize crosstalk errors in quantum information processors. We demonstrate our methods on a two-qubit trapped-ion processor and a two-qubit subsystem of a superconducting transmon processor.