论文标题
非热二阶皮肤和拓扑模式
Non-Hermitian second-order skin and topological modes
论文作者
论文摘要
非富米系统中的皮肤效应和拓扑边缘状态已经进行了充分研究，最近在非铁族系统中也提出了二阶皮肤效应和角落模式。在本文中，我们构建了嵌套的紧密结合形式主义，以分析研究二阶角模式，这是对无需其他假设的通用非官方紧密结合模型的直接描述。在这种形式主义中，我们获得了非热式四波段模型的二阶拓扑零能量角模式的确切解决方案。我们为四个波段模型和非富度二维（2D）外部模型验证了混合皮肤拐角模式中的嵌套紧密结合形式主义。此外，我们精确地说明了由二阶皮肤效应引起的角度模式，以通过嵌套的紧密结合形式形式为最简单的2D非热模型。
The skin effect and topological edge states in non-Hermitian system have been well-studied, and the second-order skin effect and corner modes have also been proposed in non-Hermitian system recently. In this paper, we construct the nested tight-binding formalism to research the second-order corner modes analytically, which is a direct description of the generic non-Hermitian tight-binding model without other assumptions. Within this formalism, we obtain the exact solutions of second-order topological zero-energy corner modes for the non-Hermitian four-band model. We validate the nested tight-binding formalism in the hybrid skin-topological corner modes for the four-band model and a non-Hermitian two-dimensional (2D) extrinsic model. In addition, we exactly illustrate the corner modes induced by second-order skin effect for a simplest 2D non-Hermitian model by the nested tight-binding formalism.
