Measuring the Capabilities of Quantum Computers - Tim Proctor

Abstract:
Quantum computers can now run interesting programs, but each processor’s capability-the set of programs that it can run successfully-is limited by hardware errors. These errors can be complicated, making it difficult to accurately predict a processor’s capability. Benchmarks can be used to measure capability directly, but current benchmarks have limited flexibility and scale poorly to many-qubit processors. In this talk, I will show how to construct scalable, efficiently verifiable benchmarks based on any program by using a technique that we call circuit mirroring. I will present the results of experiments in which we used these benchmarks to map out the capabilities of publicly available processors, and to measure the impact of program structure on each one. I will then show how circuit mirroring can be used to efficiently estimate the execution fidelity of both n-qubit circuit layers and entire quantum circuits - and how it therefore enables efficient verification of algorithms run on any number of qubits.
Bio:
Timothy Proctor is a staff scientist at the Quantum Performance Laboratory (QPL) of Sandia National Laboratories. Timothy’s primary research interests are quantum computer characterization, benchmarking, and verification. Timothy obtained his PhD in 2016 from the University of Leeds, in the UK, where he developed a theory for quantum-enhanced sensor networks.
References:
Nature Physics 18 75-79 (2022) [www.nature.com...], arXiv:2204.07568 (2022), arXiv:2112.09853 (2021), and arXiv:2207.07272 (2022).