Discrimination of correlated and entangling quantum channels with selective process tomography

TL;DR

This paper introduces a new quantum channel discrimination protocol using direct characterization of quantum dynamics (DCQD) codes, enabling efficient differentiation of entangling and correlated quantum processes with fewer measurements.

Contribution

It presents a novel selective process tomography method leveraging DCQD codes for improved discrimination of quantum channels, especially in noisy environments.

Findings

Requires few measurement configurations for low false alarm rate

DCQD encoding enhances protocol resilience to hidden noise sources

Effective in distinguishing correlated crosstalk from uncorrelated noise

Abstract

The accurate and reliable characterization of quantum dynamical processes underlies efforts to validate quantum technologies, where discrimination between competing models of observed behaviors inform efforts to fabricate and operate qubit devices. We present a novel protocol for quantum channel discrimination that leverages advances in direct characterization of quantum dynamics (DCQD) codes. We demonstrate that DCQD codes enable selective process tomography to improve discrimination between entangling and correlated quantum dynamics. Numerical simulations show selective process tomography requires only a few measurement configurations to achieve a low false alarm rate and that the DCQD encoding improves the resilience of the protocol to hidden sources of noise. Our results show that selective process tomography with DCQD codes is useful for efficiently distinguishing sources of correlated crosstalk from uncorrelated noise in current and future experimental platforms.