Verification of independent quantum devices
Chiara Greganti, Tommaso F. Demarie, Martin Ringbauer, Jonathan A. Jones, Valeria Saggio, Irati Alonso Calafell, Lee A. Rozema, Alexander Erhard, M. Meth, Lukas Postler, Roman Stricker, Philipp Claudius Schindler, R. Blatt, Thomas Monz, Philip John Walther, Joseph F. Fitzsimons · arXiv (Cornell University) · 2019
Quantum computers are on the brink of surpassing the capabilities of even the most powerful classical computers. This naturally raises the question of how one can trust the results of a quantum computer when they cannot be compared to classical simulation. Here we present a scalable verification technique that exploits the principles of measurement-based quantum computing to link quantum circuits of different input size, depth, and structure. Our approach enables consistency checks of quantum computations within a device, as well as between independent devices. We showcase our protocol by applying it to five state-of-the-art quantum processors, based on four distinct physical architectures: nuclear magnetic resonance, superconducting circuits, trapped ions, and photonics, with up to 6 qubits and more than 200 distinct circuits.