关键词: partially entangled state, teleportation, CNOT gate, positive operator valued measurement

Abstract: This paper considers the teleportation of quantum controlled-Not (CNOT) gate by using partially entangled states. Different from the known probability schemes, it presents a method for teleporting a CNOT gate with unit fidelity and unit probability by using two partially entangled pairs as quantum channel. The method is applicable to any two partially entangled pairs satisfying the condition that their smaller Schmidt coefficients $\mu$ and $\nu$ are ($2\mu + 2\nu - 2\mu\nu - 1)≥0$. In this scheme, the sender's local generalized measurement described by a positive operator valued measurement (POVM) lies at the heart. It constructs the required POVM. It also puts forward a scheme for teleporting a CNOT with two targets gate with unit fidelity by using same quantum channel. With assistance of local operations and classical communications, three spatially separated users are able to complete the teleportation of a CNOT with two targets gate with probability of $(2\mu + 2\nu- 1)$. With a proper value of $\mu$ and $\nu$, the probability could reach nearly 1.

Key words: partially entangled state, teleportation, CNOT gate, positive operator valued measurement