Improving the maximum transmission distance of coutinuous variable no-switching QKD protocol
Xu Bing-Jie, Tang Chun-Ming, Hui Chen, Wenzheng Zhang, Fu-Chen Zhu · Acta Physica Sinica · 2013
Developing quantum key distribution (QKD) protocols that can resist losses and noises is of great importance in practice. We show that the maximum transmission distance and tolerable excess noise of the no-switching CV-QKD protocol can be dramatically increased by using a noiseless linear amplifier (NLA). It is proved that an NLA with a gain g can increase the maximum transmission distance by 20 log10g/α km, where α=0.2 dB/km is the loss coefficient of the fiber channel.