论文标题
带有张量单极的四维半学：从表面状态到拓扑响应
Four-dimensional semimetals with tensor monopoles: From surface states to topological responses
论文作者
论文摘要
量子异常为探索拓扑半学中的运输现象提供了有用的指南。在这项工作中，我们引入了一个模型，描述了四个空间维度的半学，其淋巴结在动量空间中的作用像张量单孔。该系统显示出表现出单极到单核相变的偏移，这表明，拓扑dixmier-douady不变性以及其边界上相关的表面状态的变化表示。我们使用该模型揭示了有趣的“ 4D奇偶磁效应”，该模型源于奇偶校型异常。在这种效果中，在磁扰动的存在下，在时间调节时会诱导拓扑电流。除了其在凝结物质和量子场理论中的理论意义外，我们的模型所揭示的特殊的4D磁效应可以通过模拟合成物质中的较高维度的半学来衡量。
Quantum anomalies offer a useful guide for the exploration of transport phenomena in topological semimetals. In this work, we introduce a model describing a semimetal in four spatial dimensions, whose nodal points act like tensor monopoles in momentum space. This system is shown to exhibit monopole-to-monopole phase transitions, as signaled by a change in the value of the topological Dixmier-Douady invariant as well as by the associated surface states on its boundary. We use this model to reveal an intriguing "4D parity magnetic effect", which stems from a parity-type anomaly. In this effect, topological currents are induced upon time-modulating the separation between the fictitious monopoles in the presence of a magnetic perturbation. Besides its theoretical implications in both condensed matter and quantum field theory, the peculiar 4D magnetic effect revealed by our model could be measured by simulating higher-dimensional semimetals in synthetic matter.
