Quantum gate verification and its application in property testing

TL;DR

This paper develops a comprehensive framework for verifying quantum gates, providing efficient strategies for various gate types and applications in property testing and entanglement detection, crucial for quantum device benchmarking.

Contribution

It introduces a general, efficient framework for quantum gate verification applicable to multiple gate types and scenarios, including optimal strategies with local operations.

Findings

Efficient verification protocols for single qubit, qudit, and multi-qubit gates.

Optimal strategies with local operations for gate verification.

Application of verification methods to detect entanglement-preserving properties.

Abstract

To guarantee the normal functioning of quantum devices in different scenarios, appropriate benchmarking tool kits are quite significant. Inspired by the recent progress on quantum state verification, here we establish a general framework of verifying a target unitary gate. In both the non-adversarial and adversarial scenarios, we provide efficient methods to evaluate the performance of verification strategies for any qudit unitary gate. Furthermore, we figure out the optimal strategy and its realization with local operations. Specifically, for the commonly-used quantum gates like single qubit and qudit gates, multi-qubit Clifford gates, and multi-qubit Controlled-Z(X) gates, we provide efficient verification protocols. Besides, we discuss the application of gate verification for the detection of entanglement-preserving property of quantum channels and further quantify the robustness measure of them. We believe that the gate verification is a promising way to benchmark a large-scale quantum circuit as well as to test its property.