Direct observation of sub-binomial light
Direct observation of sub-binomial light
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DOI：
10.1103/physrevlett.110.173602
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发表时间：
2013-02
期刊：
影响因子：
--
通讯作者：
T. Bartley;G. Donati;Xian-min Jin;A. Datta;M. Barbieri;I. Walmsley
中科院分区：
文献类型：
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作者：
T. Bartley;G. Donati;Xian-min Jin;A. Datta;M. Barbieri;I. Walmsley
非经典光态是密码学、计算和计量标准定义等量子技术的必要资源。区分非经典状态和那些可以在不引用量子力学的情况下描述的状态，既是一项必要的实际任务，也是一项基本感兴趣的任务。一般说来，非经典的特征产生于用于描述状态的准概率分布的明显病态行为。因此，尽管状态的层析重建足以显示非经典，但直接探测开-关探测器的光子计数统计通常更方便。这是由Mandel q参数qm=〈Δn〉/〈n〉-1表示的，它对于非经典态产生的亚泊松统计量是负的。然而，当使用多路开关探测器阵列来测量具有多个光子的状态时，Mandel Q参数可能会失败；以这种方式分裂可能会破坏其原始统计数据。一个新的参数qb=N〈(Δc)2〉/〈c〉(N-〈c〉)可以用来直接从这种点击统计中判断非经典。对于QB；lt；；0，这样的统计被认为是亚二项式的，因此产生于非经典状态。
Nonclassical states of light are necessary resources for quantum technologies such as cryptography, computation and the definition of metrological standards. Distinguishing nonclassical states from those that can be described without invoking quantum mechanics is both a necessary practical task and of fundamental interest. In general, signatures of nonclassicality arise from apparently pathological behaviour of the quasi-probability distributions used to describe the states. While tomographic reconstruction of the state is therefore sufficient to show nonclassicality, it is often more convenient to probe photon-counting statistics of on-off detectors directly. This is formalised by the Mandel Q-parameter QM = 〈Δn〉 / 〈n〉 - 1, which is negative for sub-Poissonian statistics arising from nonclassical states. However, the Mandel Q-parameter can fail when using a multiplexed array of on-off detectors to measure states with several photons; splitting in this manner can corrupt its original statistics. A new parameter, QB = N 〈(Δ c) 2 〉 / 〈 c 〉 (N - 〈 c 〉) can be used to witness nonclassicality directly from such click statistics. For QB <; 0, such statistics are thus deemed sub-binomial and therefore arise from a nonclassical state.