Efficient Noise and Fidelity Estimation of Fault-Tolerant Quantum Circuits

Lunch will be served. 

Abstract:

Benchmarking physical devices and verifying logical algorithms are important tasks for scalable fault-tolerant quantum computing. While numerous protocols exist for benchmarking devices before operating on actual algorithms, we investigate whether online benchmarking can be performed for both physical and logical errors in fault-tolerant circuits. We map general fault-tolerant Clifford circuits to subsystem codes using the spacetime code formalism and propose a scheme of estimating Pauli noise in Clifford circuits using syndrome data during active error correction. Furthermore, we show that we could rigorously predict logical process fidelities of fault-tolerant Clifford circuits that happen during the algorithm without running extra circuits. This provides a way of characterizing physical components of the device to help gate tune-up, improve decoding accuracy, and verify logical circuits through efficient classical processing of the syndrome data.