面向远程量子通信的量子中继与量子U盘

Towards long-distance quantum communication:Quantum repeaters and transportable quantum memories

量子不可克隆定律赋予了量子通信基于物理学原理的安全性,其代价是长程传输的光子损耗不能使用传统的中继放大器来克服.量子中继及量子U盘是实现远程量子通信的两条可行的技术路线,近期本团队在这两条路线上都取得了显著进展:首次基于吸收型存储器建立多模式量子中继,并将相干光存储时间提升至1 h.本文介绍了量子通信、量子中继及量子U盘的基本原理,在此基础上介绍近期本团队取得的相关成果.

The non-cloning theorem provides the unconditional security for quantum communication but forbids the use of classical amplifiers.Therefore,the inevitable channel loss prevents the long-distance quantum communication.Protocols involving quantum memories can overcome this problem through the approach of quantum repeaters and transportable quantum memories.Based on rare-earth-ion doped crystals,we recently demonstrate an elementary link of a quantum repeater based on absorptive quantum memories and extend the optical storage time to 1 h.Here we provide a brief introduction to quantum communication,quantum repeaters and transportable quantum memories.Based on this,we review our recent achievements in this field.