The classical capacity for the quantum Markov channel of continuous   variables
  Quantum communications using continuous variables are quite mature experimental techniques and the relevant theories have been extensively investigated with various methods. In this paper, we study the continuous variable quantum channels from a different angle, i.e., by exploring master equations. And we finally give explicitly the capacity of the channel we are studying. By the end of this paper, we derive the criterion for the optimal capacities of the Gaussian channel versus its fidelity. 
Tao Qin, Meisheng Zhao and Yongde Zhang