Theoretical and Experimental Perspectives of Quantum Verification

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 the 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 of the correctness of its output, and propose minimal demonstrations on present-day devices.