A control protocol of finite dimensional quantum systems
  An exact and analytic control protocol of two types of finite dimensional quantum systems is proposed. The system can be drive to an arbitrary target state using cosine classical fields in finite cycles. The control parameters which are time periods of interaction between systems and control fields in each cycles are connected with the probability amplitudes of target states via triangular functions and can be determined analytically. 
Jianju Tang and H. C. Fu
quant-ph