Finite-Key Analysis for a Practical High-Dimensional Quantum Key Distribution System Based on Time-Phase States

• 来源期刊: 中国物理快报（英文版）
• 年，卷（期）: 2019,（4）
• 页码范围: 1-5
• 页数: 5页
• 语种: 英文
• DOI: 10.1088/0256-307X/36/4/040301

摘要

High-dimensional quantum states key distribution (HD-QKD) can enable more than one bit per photon and tolerate more noise.Recently,a practical HD-QKD system based on time-phase states has provided a secret key at Mbps over metropolitan distances.For the purposes of further improving the secret key rate of a practical HD-QKD system,we make two main contributions in this work.Firstly,we present an improved parameter estimation for this system in the finite-key scenario based on the Chernoff bound and the improved Chernoff bound.Secondly,we analyze how the dimension d affects the performance of the practical HD-QKD system.We present numerical simulations about the secret key rate of the practical HD-QKD system based on different parameter estimation methods.It is found that using the improved Chernoff bound can improve the secret key rate and maximum channel loss of the practical HD-QKD system.In addition,a mixture of the 4-level and 8-level practical HD-QKD system can provide better performance in terms of the key generation rate over metropolitan distances.