论文标题
高维角度两光子干扰和角Qudit状态
High-dimensional Angular Two-Photon Interference and Angular Qudit States
论文作者
论文摘要
使用角度位置 - 角度动量纠缠光子，我们提出了一个实验，以生成$ d $二维量子系统的最大纠缠状态，即所谓的Qudits，通过利用参数下转换光子的相关性。每个双光子的臂中包含$ n $ slits的角衍射掩模定义了尺寸的Qudit $ n^2 $的Qudit空间，并由光子的替代途径跨越。由于相匹配条件，双光子只能通过对称的角缝隙传递，从而在这些不同的路径之间产生最大纠缠的状态，这些路径可以通过巧合计数通过高阶两光子干扰条来检测。报告了$ n $ n = 2、4、5、6、10 $的$ n $角缝隙的数值结果，分别对应于dimension $ d = n^2 = 4,16,25、36,100 $的Qudit Hilbert Spaces。我们讨论了使用空间光调节器（SLM）和Spontaneouos参数降低转换（SPDC）生成的双光仪的实验实现的相关实验参数。可以根据并发量来量化Qudit国家的纠缠，这可以根据干扰条纹的可见性或使用纠缠证人来表示。这些结果提供了一种在高维中制备纠缠量子状态的附加方法，这是量子模拟和量子信息协议的基本资源。
Using angular position-orbital angular momentum entangled photons, we propose an experiment to generate maximally entangled states of $D$-dimensional quantum systems, the so called qudits, by exploiting correlations of parametric down-converted photons. Angular diffraction masks containing $N$-slits in the arms of each twin photon define a qudit space of dimension $N^2$, spanned by the alternative pathways of the photons. Due to phase-matching conditions, the twin photons will pass only by symmetrically opposite angular slits, generating maximally entangled states between these different paths, which can be detected by high-order two-photon interference fringes via coincidence counts. Numerical results for $N$ angular slits with $N = 2, 4, 5, 6, 10$ are reported, corresponding to qudit Hilbert spaces of dimension $D=N^2=4,16,25, 36,100$, respectively. We discuss relevant experimental parameters for an experimental implementation of the proposed scheme using Spatial Light Modulators (SLMs), and twin-photons produced by Spontaneouos Parametric Down Conversion (SPDC). The entanglement of the qudit state can be quantified in terms of the Concurrence, which can be expressed in terms of the visibility of the interference fringes, or by using Entanglement Witnesses. These results provide an additional means for preparing entangled quantum states in high-dimensions, a fundamental resource for quantum simulation and quantum information protocols.
