Experimental Characterization of Crosstalk Errors with Simultaneous Gate Set Tomography

TL;DR

This paper demonstrates how gate set tomography can be used to identify and characterize crosstalk errors in multiqubit quantum processors, providing detailed insights into error correlations.

Contribution

It introduces a method to use simultaneous gate set tomography for detailed crosstalk error characterization in quantum devices.

Findings

Successfully applied to trapped-ion and superconducting qubits

Able to distinguish different types of crosstalk errors

Provides detailed error correlation information

Abstract

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.