量子通信研究的若干问题

Some Problems in Research of Quantum Communication

1935年A.Einstein、B.Podolsky和N.Rosen三人发表合写文章"量子力学对物理实在的描述是否完备?"该文的局域性原则与他的狭义相对论(SR)相呼应,但与量子力学(QM)不一致。1951年D.Bohm对EPR思维作了现代意义上的陈述,实际上启动了量子纠缠态研究。在此基础上,1965年J.Bell提出了后来称为Bell不等式的隐变量理论,而在1981年-1982年A.Aspect做了多个精确实验,结果与Bell不等式不符,而与QM一致。因此,双粒子系统中存在QM预期的奇异相关,其中的超空间(超距)作用却与EPR思维矛盾。在后来数十年中,Bell型实验常盛不衰,互相纠缠的光子间隔由Aspect时的15m逐步加大到144km,而在2017年由中国量子卫星扩展到1200km,十分惊人。EPR论文的错误对科学研究提供了深刻的教益。近年来量子通信技术的发展,就是建筑在量子非局域性和量子纠缠的基础上的。量子信息学(QIT)有三个主要研究方向——量子计算、量子通信和量子雷达。量子通信的关键点在于必须有绝对保密性。但这在实际上很难,故迄今不能说这问题已经解决。因此,我们认为在2017年量子通信才获很大成就。

In 1935,A.Einstein together with B.Podolsky and N.Rosen,published the thesis“Can quantum mechanical description of physical reality be considered complete?”The locality principle in this thesis echoed his Special Relativity(SR),but it lack cosistency with the Quantum Mechanics(QM).D.Bohm made statements upon the EPR thinking idea experiment in modern way in 1951,he made a groundbreaking start in quantum entangle state research.Based here,J.Bell presented Bell’s unequality through hidden variable theory in 1965,yet during 1981 to 1982 A.Aspect did several high accrate experiments with the results that went against Bell’s unequality but along with QM.Then we know that the two particles system resulted the peculiar correlations that QM predicted,and it existed the ultra-space effect were in contradiction with the EPR thinking.In last several decades,the Bell-type experiments was continue working,the distance of entangled photons from 15m by Aspect growed to 144km,and in 2017 it reached 1200km by the quantum communication satallite of PRC,it was astonishing achievements.The mistakes of EPR thesis gives us the deep enlightenment in scientific study.Recently,the developments of quantum communication technology was based upon the quantum non-locality and the quantum entanglement.There are three situations in Quantum Information Technology(QIT)research:quantum computation,quantum communication and quantum radar.The key problem of the quantum communication is that must be secret absolutely.But it is a very difficult technology in practise,no one can say it’s a solved problem.Under this consideration,we believe that the quantum communication experiment was a great success only in 2017.