Characterization of addressability by simultaneous randomized benchmarking

TL;DR

This paper introduces a benchmarking protocol to quantify addressability in multi-qubit systems, demonstrated on superconducting qubits, revealing how cross-talk affects gate fidelities and system control.

Contribution

The paper presents a novel randomized benchmarking protocol that measures addressability by comparing individual and simultaneous qubit fidelities in superconducting systems.

Findings

Addressability varies with cross-talk levels.

The protocol accurately detects residual coupling effects.

Results align with simple interaction models.

Abstract

The control and handling of errors arising from cross-talk and unwanted interactions in multi-qubit systems is an important issue in quantum information processing architectures. We introduce a benchmarking protocol that provides information about the amount of addressability present in the system and implement it on coupled superconducting qubits. The protocol consists of randomized benchmarking each qubit individually and then simultaneously, and the amount of addressability is related to the difference of the average gate fidelities of those experiments. We present the results on two similar samples with different amounts of cross-talk and unwanted interactions, which agree with predictions based on simple models for the amount of residual coupling.