纠缠压缩真空态的纠缠转移

通过分析光学分束器对压缩真空态光场的作用,发现如果分束器的输入光是两束具有同样振幅和相位的单模压缩真空态光场,则输出光为双模压缩真空态光场;若分束器的输入光是两束具有同样振幅但有π相位差的单模压缩真空态光场,则输出光仍为两束单模压缩真空态光场.对于双模压缩真空态光场,每个模中容纳的光子数可以是基数或偶数.而对于单模压缩真空态光场,每个模中只能包含偶数个光子.根据这些结果,提出了一个纠缠转移的方案.在这个方案中,两个纠缠压缩真空态光场被用作量子信道,通过利用光学分束器作用和光子数探测的方法,并在经典通讯的帮助下,实现了三个通讯伙伴之间的纠缠转移.

Entanglement Diversion of Entangled Squeezed Vacuum State

By analyzing the action of a beam splitter on squeezed vacuum states (SVSs), it is found that, if the two input light beams of the beam splitter have the same squeezing amplitude and phase, the output state is a two-mode SVS. If the two input light beams of the beam splitter have the same squeezing amplitude but a phase difference of π, the output state is a direct product state of two single-mode SVSs. In the two-mode SVS, each mode has the same photon number with both even and odd photons, while the single-mode SVS which contains only even-number photon in the photon number-state representation. Based on these results, a scheme to divert the entanglement of entangled SVS from its initial locations to another location is suggested. In this scheme, the two SVSs are utilized as the quantum channel. The process of the entanglement diversion is achieved by using the 50/50 symmetric beam splitters and the photon detectors with the help of classical information.