粒子物理中量子纠缠的历史起源

Historic Origin of Quantum Entanglement in Particle Physics

本文系统深入地梳理了粒子物理中量子纠缠的历史起源。1957年,玻姆和阿哈诺罗夫指出,1949年吴健雄和萨克诺夫的实验实现了爱因斯坦–波多尔斯基–罗森关联。事实上,这是历史上第一次在实验中明确实现空间分离的量子纠缠。惠勒最早建议这个实验,作为对量子电动力学的检验,但是计算有误,正确的理论计算来自沃德和普赖斯,以及斯奈德、帕斯特纳克和奥恩博斯特尔,也符合杨振宁1949年的选择定则。1964年贝尔不等式发表后,人们考虑,它是否可以通过吴–萨克诺夫实验检验。这推动了该领域的发展,吴健雄小组也做了新的实验。1957年,李政道、厄梅和杨振宁确立了K介子的量子力学形式,并发现中性K介子是一个双态系统。1958年,基于与杨振宁1949年选择定则类似的方法,戈德哈贝尔、李政道和杨振宁最早写下K介子对的纠缠态,其中单个K介子可以带电,也可以电中性。这首次给出光子以外的高能粒子的内部自由度纠缠。1960年,作为没有发表的工作,李政道和杨振宁又讨论了中性K介子对的纠缠态。本文也顺便介绍了几位物理学家,特别是沃德。

The historic origin of quantum entanglement in particle physics is studied systematically and in depth.In 1957,Bohm and Aharonov noted that the 1950 Wu-Shaknov experiment had realized the discrete version of the Einstein-Podolsky-Rosen correlation.Indeed this experiment was definitely the first experimental realization of spatially separated quantum entanglement in history.Such an experiment had been proposed by Wheeler,as a test of quantum electrodynamics,but his calculation was erroneous.The correct theoretical calculations were made by Ward and Pryce and also by Snyder,Pasternack and Hornbostel.The entangled state of the photons also satisfies the selection rule of C.N.Yang in 1949.After the publication of Bell inequality in 1964,discussions on whether Wu-Shaknov experiment can be exploited in testing the inequality inspired the progress of this field,and a new experiment was done by Wu’s group.In 1957,Lee,Oehme and Yang established the quantum mechanical formulation of the kaons,and discovered that neutral kaon is a two-state system.The following year,Goldhaber,Lee and Yang wrote down entangled states of a pair of kaons for the first time,in which each kaon is allowed to be charged or neutral,as the entanglement in internal degrees of high energy particles beyond photons written down for the first time.In 1960,as an unpublished work,Lee and Yang discussed an entangled state of a pair of neutral kaons.Such entangled kaons widely exist in meson factories later on.Several physicist are also introduced,especially Ward.