23_QSE
Efficient Quantum-State Estimation by Continuous Weak Measurement and Dynamical Control
Greg A. Smith, Andrew Silberfarb, Ivan H. Deutsch, and Poul S. Jessen
We demonstrate a fast, robust, and nondestructive protocol for quantum-state estimation based on continuous weak measurement in the presence of a controlled dynamical evolution. Our experiment uses optically probed atomic spins as a test bed and successfully reconstructs a range of trial states with fidelities of ~90%. The procedure holds promise as a practical diagnostic tool for the study of complex quantum dynamics, the testing of quantum hardware, and as a starting point for new types of quantum feedback control.