Optimal cloning of two known nonorthogonal quantum states
Wen‐Hai Zhang, Long-Bao Yu, Zhuo‐Liang Cao, Liu Ye · Physical Review A · 2012
Two known nonorthogonal quantum states can be cloned either deterministically or probabilistically. In this paper, we investigate quantum cloning by combining these two extreme cases, i.e., a trade-off between the copy fidelity and the success probability. For a special set of two known nonorthogonal quantum states, we start with an explicit unitary transformation and derive the copy fidelity as a function of the success probability. The result shows that the higher is the copy fidelity, the less is the success probability. This quantum cloning may have important applications in quantum cryptography.