Self-consistent quantum tomography with regularization

A reliable method for characterizing quantum operations that is suitable improving and validating their accuracies indispensable realizing a practical computer. Known methods are still not sufficient because they lack reliability or use in the improvement validation steps. Here we propose characterization accuracy step. First, introduce new self-consistent estimator with regularization physicality constraints designed validation. Second, mathematically prove provides estimation results stringently physical converge to gauge-equivalence class of interest at limit data size going infinity. The asymptotic convergence guarantees method, regularized ensure suitability task. We also derive rate, which would be optimal. Finally, show numerical on 1-qubit system, confirm theoretical proposed practical.