Exponential stabilization of stochastic quantum systems via combined feedback

We propose a novel control strategy by combining state feedback with noise-assisted feedback to exponentially stabilize the target eigenstate for two-level stochastic quantum systems in this paper. The state space is divided into two subspaces, and the state feedback and noise-assisted feedback work in the corresponding subspace, respectively, to achieve the faster state convergence than that of using the two feedback controls individually. We prove the exponential stabilization of target eigenstate under the combined feedback, whose the effectiveness and superiority are verified in numerical simulations.