基于光子超纠缠态的高容量量子通信研究

Photon system is the ideal information carrier in quantum communication because of its high transmission speed, low preparation cost, and weak interaction with environment noise. It can be coded in multiple degrees of freedom (DOFs), such as polarization, spatial mode, frequency, angle momentum, and time-bin DOFs. The state of a photonic quantum system simultaneously entangled in more than one DOF is called hyperentanglement, and it can increase both the channel capacity of the quantum communication and its security. It can speed up quantum computation as well. In this project, we investigate the high-capacity quantum communication assisted by photonic hyperentanglement, including: (1) Multi-photonic hyperentanglement concentration with multiple DOFs assisted by nonlinear optical property; (2) Error-detected analysis of hyperentangled states for multi-photonic system with multiple DOFs ; (3) The investigation of the high-capacity quantum communication with noise suppression and error detection. We hope that we will obtain some interesting outcomes on the high-capacity quantum communication from this project.

由于传输速度快、制备成本低、与环境噪声作用弱，光子系统成为量子通信的理想信息载体。光子具有多个可以用于信息编码的自由度，如极化、空间模式、频率、角动量、时间-能量等。光子系统在两个及其以上自由度同时存在纠缠的量子态称为超纠缠态，它可提高量子通信的容量与安全性，且能加速量子计算。本项目为基于光子超纠缠态的高容量量子通信研究。研究内容主要包括：（1）基于非线性光学效应的多光子多自由度超纠缠浓缩研究 ；（2）能探测错误的多光子多自由度超纠缠分析研究；（3）结合噪声压制和错误探测的高容量量子通信研究。通过这一研究，力争在高容量量子通信方面做出一些创新性的成果。

光子系统是量子通信的理想信息载体，它具有极化、空间模式、频率、角动量、时间-能量等多个自由度，多个自由度同时应用于量子通信可提高量子通信的容量和安全性，且能加速量子计算。本项目主要研究基于光子超纠缠态的高容量量子通信问题，具体包括：（1）基于cross-Kerr非线性的非局域两光子六比特系统超纠缠浓缩方案；（2）基于线性光学元件的光子六比特超纠缠簇态浓缩方案；（3）基于金刚石NV色芯耦合波导腔系统的两光子六比特超纠缠态分析方案；（4）基于原子系统的静态纠缠光子对的相干产生以及高效全光路由器和分束器设计。