论文标题
离散时间量子步行中三个光子的空间和极化纠缠
Spatial and polarization entanglement of three photons in a discrete-time quantum walk
论文作者
论文摘要
我们研究了在正方形晶格的最近邻居部位上执行离散时间量子步行（DTQW）的三个光子的量子纠缠。已经提出，使用线性光学元素可以实现此类DTQW设置。每个晶格位点对应于半波板和偏光束分离器的顺序作用。可以将二维DTQW映射到有效的一维DTQW，其四面硬币取决于光子的极化和运动方向。众所周知，这种系统能够在空间上纠缠两个光子，最初以可分离状态制备。我们将结果概括为三个光子的情况，以探索该设置是否可以产生不同的纠缠类别，即W和GHz状态。除空间纠缠外，我们还分析了在极化基础上纠缠的可能性。我们的结果对于实用量子技术应用所需的简单而快速生成的多部分纠缠的光子状态可能很重要。
We investigate quantum entanglement of three photons performing discrete-time quantum walk (DTQW) on the nearest-neighbor sites of a square lattice. Such a DTQW setup has already been proposed to be realizable using linear optical elements. Each lattice site corresponds to the sequential action of a half-wave plate and a polarizing beam splitter. Two-dimensional DTQW can be mapped to an effective one-dimensional DTQW with a four-sided coin that depends on the polarization and direction of motion of the photons. It is known that such a system is capable to spatially entangle two photons, prepared in a separable state initially. We generalize the result to the case of three photons to explore if distinct entanglement classes, namely W and GHZ states, can be produced by this setup. In addition to spatial entanglement, we analyze the possibility of entanglement in the polarization basis, too. Our results can be significant for a simple and fast generation of multipartite entangled photonic states demanded by practical quantum technology applications.
