The finite-time control problem of quantum systems is investigated in this paper. We first define finite-time stability and present a finite-time Lyapunov stability criterion for finite-dimensional quantum systems in coherence vector representation. Then, for two-level quantum systems, we design a continuous non-smooth control law with a state-dependent fractional power and prove the uniqueness of solutions of the system dynamics with the controller via the concept of transversality. By combining the finite-time Lyapunov stability criterion with the homogeneity theory, the finite-time convergence of the system to an eigenstate of its internal Hamiltonian is proved. Numerical results on a spin-1/2 system demonstrate the effectiveness of the proposed finite-time stabilization control scheme.

9 pages, 3 figures