Chiral bulk Landau levels and surface arcs, as the two distinctive features unique to Weyl semimetals, have each attracted enormous interest. Recent works have revealed that surface-arc modes can support one-sided chiral hinge modes, a hallmark of the three-dimensional quantum Hall effect, as a combined result of chiral Landau levels of bulk states and magnetic response of surface arcs. Here, we exploit a two-dimensional phononic crystal to construct an ideal Weyl semimetal under a pseudomagnetic field, in which a structural parameter is combined to construct a synthetic three-dimensional space. By directly measuring the acoustic pressure fields, we have not only visualized the one-sided chiral hinge modes, but also observed the quantized Landau level modes. The results pave the way to explore the high-dimensional quantum Hall physics in low-dimensional phononic platforms.

中文翻译：

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合成外尔声子晶体中表面弧的铰链模式


手性体朗道能级和表面弧作为外尔半金属独有的两个独特特征，都引起了人们的极大兴趣。最近的研究表明，表面弧模式可以支持单侧手性铰链模式，这是三维量子霍尔效应的标志，是体态手性朗道能级和表面弧磁响应的综合结果。在这里，我们利用二维声子晶体在赝磁场下构建理想的韦尔半金属，其中结构参数被组合以构建合成的三维空间。通过直接测量声压场，我们不仅可视化了单侧手性铰链模式，还观察到了量化的朗道能级模式。这些结果为探索低维声子平台中的高维量子霍尔物理铺平了道路。