Practical Fidelity Estimation for Noisy Quantum Devices Using Direct and Survival-Probability-Based Protocols
The work presents two methods for estimating quantum state fidelity without full quantum tomography: Direct Fidelity Estimation (DFE) and a survival-probability-based method. DFE estimates fidelity using importance sampling of Pauli measurements, while the second method reconstructs it from noisy evolution moments. These protocols offer experimentally relevant ways to assess device performance in the presence of noise.