Efficient measurement of quantum gate error by interleaved randomized benchmarking

TL;DR

This paper introduces a scalable protocol for accurately estimating the error rates of individual quantum gates by interleaving them with random Clifford gates, accounting for noise variations and measurement errors.

Contribution

It presents a novel interleaved randomized benchmarking method that provides bounded error estimates for quantum gates, scalable to multiple qubits.

Findings

Gate errors measured are comparable to quantum process tomography results.

The protocol accounts for state preparation and measurement errors.

It is scalable to larger quantum systems.

Abstract

We describe a scalable experimental protocol for obtaining estimates of the error rate of individual quantum computational gates. This protocol, in which random Clifford gates are interleaved between a gate of interest, provides a bounded estimate of the average error of the gate under test so long as the average variation of the noise affecting the full set of Clifford gates is small. This technique takes into account both state preparation and measurement errors and is scalable in the number of qubits. We apply this protocol to a superconducting qubit system and find gate errors that compare favorably with the gate errors extracted via quantum process tomography.