关键词: 量子通信, 纠缠交换, 量子中继

Abstract: Because the atmosphere is full of noise and interference, long-distance quantum communication in free space has become a problem. Based on the principle of entangled quantum state exchange, a quantum channel is established indirectly at both ends through two relay points, which makes the transfer of quantum information over long distances possible. By studying the quantum states of the source and the relay point under different circumstances, the quantum state of the receiving end is imposed on different logic gates for corresponding logic transform. As a result, the information sent by the source side is gotten. In addition, this paper studies the systems with N relay points and solves the problem of quantum information transmission over long distances.

Key words: quantum communication, entanglement exchange, quantum repeater