摘要
The security of quantum communication is based on the laws of quantum mechanics,which can resist attacks from any powerful classical and quantum computers.It has great potential in secure communication in the future.One well-known form of quantum communication is quantum key distribution(QKD),where random numbers are transmitted in the quantum channel to generate a shared key between two remote parties.
量子直接通信的安全容量是主信道容量和窃听者搭线信道容量的差.然而,量子信道损耗极大,丢失大量量子比特携带信息,安全容量大幅减少.本文报道了大幅度增加量子直接通信容量的INCUM技术,该技术利用随机数掩盖没有接收到的量子态,大幅增加安全容量.在该技术中,发送方先用随机数加在每个量子态上进行掩盖,只公布被接收方得到的那些量子态的随机数,而没有收到的量子态都被随机数掩盖了,窃听者得不到任何信息,安全容量得到大幅度提高.以DL04协议为例,在检测误码率为3%时,没有使用INCUM的最大传输距离为4 km,使用INCUM后传输距离增加至108 km,提高27倍,传输速率大大地增加.因此,INCUM极大拓展了量子直接通信的应用前景.
作者
Gui-Lu Long
Haoran Zhang
龙桂鲁;张浩然(State Key Laboratory of Low-dimensional Quantum Physics and Department of Physics,Tsinghua University,Beijing 100084,China;Beijing Academy of Quantum Information Sciences,Beijing 100193,China;Collaborative Innovation Center of Quantum Matter,Beijing 100084,China;Beijing National Research Center for Information Science and Technology,Beijing 100084,China)
基金
supported by the Key-Area Research and Development Program of Guangdong Province (2018B030325002)
National Key Research and Development Program of China (2017YFA0303700)
the National Natural Science Foundation of China (11974205)
Beijing Advanced Innovation Center for Future Chip (ICFC)
Tsinghua University Initiative Scientific Research Program
