Probabilistic quantum cloning of three equidistant states

Abstract

We investigate the N → M probabilistic quantum cloning of three equidistant states defined by a real number of the overlap among them. We design the most general transformation of probabilistic quantum cloning, which improves the probabilistic quantum cloning proposed in the reference (Duan and Guo. PRL. 80, 4999 (1998)). The success cloning probability of generating M copies out of N original are dependent on the numbers N and M and the sign of the overlaps among three equidistant states. Based on the most general transformation of probabilistic quantum cloning, our result suggests that the measurement operators of the unambiguous state discrimination should include the success operators and the correct operators.