Noise-resilient phase estimation with randomized compiling

Understand

We develop an error mitigation method for the control-free phase estimation.

• We prove a theorem that under the first-order correction, the noise channels with only Hermitian Kraus operators do not change the phases of a unitary operator, and therefore, the benign types of noise for phase estimation are identified.
• By using the randomized compiling protocol, we can convert the generic noise in the phase estimation circuits into stochastic Pauli noise, which satisfies the condition of our theorem.
• Thus we achieve a noise-resilient phase estimation without any quantum resource overhead.