Theoretical and Experimental Perspectives of Quantum Verification

TL;DR

This paper explores various methods for verifying quantum devices through experiments, including Hamiltonian learning, cross-device state comparison, and output correctness, emphasizing protocols using randomized measurements and proposing a centralized data repository.

Contribution

It introduces new experimental protocols for quantum verification, compares different approaches, and proposes a centralized data repository for benchmarking quantum devices.

Findings

Verification protocols using randomized measurements are effective.

A central data repository can facilitate device comparison.

Minimal demonstrations can verify quantum output correctness.

Abstract

In this perspective we discuss verification of quantum devices in the context of specific examples, formulated as proposed experiments. Our first example is verification of analog quantum simulators as Hamiltonian learning, where the input Hamiltonian as design goal is compared with the parent Hamiltonian for the quantum states prepared on the device. The second example discusses cross-device verification on the quantum level, i.e. by comparing quantum states prepared on different quantum devices. We focus in particular on protocols using randomized measurements, and we propose establishing a central data repository, where existing experimental devices and platforms can be compared. In our final example, we address verification of the output of a quantum device from a computer science perspective, addressing the question of how a user of a quantum processor can be certain about the correctness of its output, and propose minimal demonstrations on present day devices.