Real-time quantum measurement-feedback control: A non-smooth time delay control approach

Abstract

This paper solves the problem of real-time measurementfeedback control for quantum systems, in which the time to compute the filter-based control input is taken into account by considering the input delay. It starts with a new Lyapunov-LaSalle-like theorem for delay-dependent stochastic stability of a class of time delay stochastic nonlinear systems. Non-smooth time delay control is then constructed to compensate for the control-computation time, that is known but arbitrarily long, while globally stabilize the quantum filters almost surely. The non-smooth property enables the proposed control to deal with the symmetric topology of filter state space. The effectiveness of nonsmooth time delay control is illustrated through the control design for the Spin-1/2 systems. Simulation results are presented and discussed.