Bounding Quantum Gate Error Rate Based on Reported Average Fidelity
Advances in Quantum Algorithms and Devices: Bounding Quantum Gate Error Rate Based on Reported Average Fidelity
Remarkable experimental advances in quantum computing are exemplified by recent announcements of impressive gate fidelities exceeding 99.9% for single-qubit gates and exceeding 99% for two-qubit gates. These reported high numbers engender optimism that fault-tolerant quantum computing is within reach. Here we convert reported gate fidelity to a bound on worst case quantum gate error rate, which is appropriate to assess progress towards fault-tolerance targets and is greater by orders of magnitude. We prove that this bound scales optimally. Our work demonstrates the huge divide between reported gate fidelities and requisite gate performance.