清华物理系量子信息研究的新进展

在清华大学物理系成立60周年之际,我们对近年来清华大学物理系量子信息研究的主要进展情况作一介绍,包括量子搜索算法研究,核磁共振量子计算的实验研究,量子通讯的理论与实验研究.在量子搜索算法研究方面,我们提出了量子搜索算法的相位匹配,纠正了当时的一种错误观点,并且提出了一种成功率为100%的量子搜索算法,改进了Grover算法;在核磁共振量子计算实验方面,我们实现了2到7个量子比特的多种量子算法的实验演示;在量子通讯方面,我们提出了分布式传输的量子通讯的思想,应用于量子密钥分配、量子秘密共享、量子直接安全通讯等方面,构造了多个量子通讯的理论方案.在实验室,我们实现了2米距离的空间量子密码通讯的演示实验.

Recent progress in quantum information research in the Deapartment of Physics, Tsinghua University

At the occasion of the 60 anniversary of the department, we give a brief introduction of the recent progress on quantum information research over the last few years, including quantum search algorithm, nuclear magnetic resonnace quantum computing experiment, quantum communication theory and experiment. In quan- tum algorithm study, we put forward the concept of phase matching in quantum searching, corrected a mistake at that time, and furthermore we constructed a quantum search algorithm with 100% successful rate which improves the Grover algorithm. In NMR quantum computing, we have demonstrated several quantum algorithms u- sing 2 to 7 qubits NMR systems. In quantum communication, we have proposed the idea of distributed quantum communication and applied the idea to quantum key distribution, quantum secret sharing and quantum secure direct communication. We have constructed dozens of quantum communication protocols based on this idea. We have demonstrated quantum communication over a 2m distance in free space in laboratory.