Scatterings and transport in Weyl semimetals have caught growing attention in condensed matter physics, with observables including chiral zero modes and the associated magnetoresistance and chiral magnetic effects. Measurement of electrical conductance is usually performed in these studies, which, however, cannot resolve the momentum of electrons, preventing direct observation of the phase singularities in scattering matrix associated with Weyl point. Here we experimentally demonstrate a helical phase distribution in the angle (momentum) resolved scattering matrix of electromagnetic waves in a photonic Weyl metamaterial. It further leads to spiraling guided modes in an air gap sandwiched between a Weyl metamaterial and a metal plate. Benefiting from the alignment-free feature of angular vortical reflection, our findings establish a new platform in manipulating optical angular momenta with photonic Weyl systems.

中文翻译：

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带有Weyl超材料的涡旋反射和费米弧螺旋

魏尔半金属中的散射和迁移在凝聚态物理中引起了越来越多的关注，可观察到的包括手性零模以及相关的磁阻和手性磁效应。电导率的测量通常在这些研究中进行，但是，这无法解决电子的动量，从而无法直接观察与Weyl点相关的散射矩阵中的相奇异点。在这里，我们通过实验证明了光子Weyl超材料中电磁波在角度（动量）分辨的散射矩阵中的螺旋相位分布。它进一步导致夹在Weyl超材料和金属板之间的气隙中的螺旋引导模式。得益于角涡旋反射的无对准特性，