Characterizing Quantum Gates via Randomized Benchmarking

TL;DR

This paper discusses an improved, scalable randomized benchmarking protocol for quantum gates that accounts for various noise types and errors, providing reliable estimates of gate fidelity in quantum computing.

Contribution

It extends the randomized benchmarking protocol to be scalable and robust against weak time and gate-dependent noise, with a detailed analysis of error conditions and measurement errors.

Findings

Protocol accommodates weak time and gate-dependent noise

Provides a sufficient condition for protocol applicability

Establishes connection between error rate and diamond norm in special cases

Abstract

We describe and expand upon the scalable randomized benchmarking protocol proposed in Phys. Rev. Lett. 106, 180504 (2011) which provides a method for benchmarking quantum gates and estimating the gate-dependence of the noise. The protocol allows the noise to have weak time and gate-dependence, and we provide a sufficient condition for the applicability of the protocol in terms of the average variation of the noise. We discuss how state preparation and measurement errors are taken into account and provide a complete proof of the scalability of the protocol. We establish a connection in special cases between the error rate provided by this protocol and the error strength measured using the diamond norm distance.