A Convergent control strategy for quantum systems
  In the interaction picture, a sufficient and necessary condition that guarantees the convergence of closed quantum control system is proposed in this paper. Theoretical derivation and the proof show that it is possible to achieve the convergence to the target state by constructing an observable operator in an energy function and selecting control Hamiltonians. Numerical simulation experiments on a four-level system verify the effectiveness of the proposed control strategy. 
Shuang Cong, Yuesheng Lou, Jianxiu Liu, Sen Kuang
math-ph math.MP quant-ph