九十年代以来,随着量子通信和量子计算的发展,人们发现纠缠是量子信息学中的最为重要的工具之一,它被广泛应用于量子隐形传态、量子密集编码、量子纠缠交换、量子密码等众多量子通信和量子计算过程之中。因此,有关量子纠缠态的制备、识别和测量也成为影响量子信息发展的重要环节。实验上最易实现的是参量下转换过程产生的双光子纠缠态,即 Bell 态。相应的识别和测量方面,使用线性光学元件无法识别全部四个 Bell 态,只有使用原子的双光子吸收等非线性过程才能实现完整的 Bell 态识别和测量。最近．两种采用非线性 Kerr 元件的测量方案被分别提出。这里,我们提出一种同样使用 Kerr 元件的非破坏性的 Bell 识别方案．并将这种方案推广到所有的偶数粒子 GHZ 态的非破坏性识别。
A pair of photons called signal and idler photons, respectively, are produced through the nonlinear process of type I spontaneous parametric down conversion in BBO crystal pumped by the second harmonic wave of a Ti...
详细信息
A pair of photons called signal and idler photons, respectively, are produced through the nonlinear process of type I spontaneous parametric down conversion in BBO crystal pumped by the second harmonic wave of a Ti∶sapphire femtosecond laser pulse. The two order interference phenomenon of the signal photon in Michelson interferometer is observed and give an analysis in detail.
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