Real-time quantum state estimation in circuit QED via the Bayesian approach

Using a superconducting circuit QED device, we present a theoretical study of real-time quantum state estimation via the quantum Bayesian approach. Suitable conditions under which the quantum Bayesian approach can accurately update the density matrix of the qubit are analyzed. We also consider the correlation between some basic and physically meaningful parameters of the circuit QED and the performance of the Bayesian approach. Our results advance the understanding of the quantum Bayesian approach.