A Study on the Twin-Field QKD Protocol

• Main Authors: Yao-Ting Lin, 林耀廷
• Other Authors: 管希聖
• Format: Others
• Language: en_US
• Published: 2019
• Online Access: http://ndltd.ncl.edu.tw/handle/7t2ezh

碩士 === 國立臺灣大學 === 物理學研究所 === 107 === Recently, a new protocol, the twin-field QKD (TFQKD) protocol, has been proposed and is claimed to overcome the fundamental limits of quantum repeater-less communications. Soon after its appearance, the related research has gained lot of focus. In this thesis, we first review the existing protocol and make a comparison between them and the TFQKD protocol. Furthermore, we classify recent papers related to the TFQKD protocols into two main types: the phase-matching-type (PM) protocol and the sending-or-not-sending-type (SNS) protocol. We review the arguments for the security and simulate the key rate versus distance for both types of protocols under different conditions. Then we compare their performances between the two types of protocols. To investigate the feasibility for practical implementation, we also discuss the finite-size effect for the post-processing block size. The results show both protocols are capable of overcoming the repeater-less bound with current devices and technology.