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arXiv 2307.07548math-phcond-mat.mes-hallmath.MP
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具有可变质量的二维Dirac算子的拓扑及其在浅水波中的应用

Topology of 2D Dirac operators with variable mass and an application to shallow-water waves

Sylvain Rossi, Alessandro Tarantola

AI总结:

针对恒定质量二维Dirac算子因非紧致布里渊区无法定义体不变量、违反体边对应关系的问题,提出质量沿垂直方向空间变化的方法,定义了匹配的体边指标并验证体边对应,且成功推广至浅水波模型。

摘要:

平面上具有恒定(正)质量的Dirac算子是一种陈绝缘体,属于Kitaev周期表的D类。尽管该系统结构简单,但其拓扑行为存在问题:非紧致布里渊区导致无法定义体不变量,若直接将该模型置于带边界的流形上,会违反体边对应关系(BEC)。我们通过让质量在垂直方向上空间变化,在原始模型与其负质量对应模型之间插值,解决了这两个问题。此时可定义合理的体指标和边指标,且二者被证明是相等的,从而体现了体边对应关系。浅水波模型与二维有质量Dirac算子存在相同的问题。相似的问题对应相似的解决方案,将上述方法推广到该场景中,确实得到了合理的指标以及另一组体边对应关系实例。

英文摘要:

A Dirac operator on the plane with constant (positive) mass is a Chern insulator, sitting in class D of the Kitaev table. Despite its simplicity, this system is topologically ill-behaved: the non-compact Brillouin zone prevents definition of a bulk invariant, and naively placing the model on a manifold with boundary results in violations of the bulk-edge correspondence (BEC). We overcome both issues by letting the mass spatially vary in the vertical direction, interpolating between the original model and its negative-mass counterpart. Proper bulk and edge indices can now be defined. They are shown to coincide, thereby embodying BEC. The shallow-water model exhibits the same illnesses as the 2D massive Dirac. Identical problems suggest identical solutions, and indeed extending the approach above to this setting yields proper indices and another instance of BEC.

机构、总结、中文摘要均由AI分析而来,可能存在错误,请以论文正文为准。

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