用于三维手性高阶拓扑绝缘体的共线交替磁性
Collinear altermagnetism for 3D chiral higher-order topological insulators
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中文总结 AI 辅助
该研究提出利用共线交替磁性构建三维手性高阶拓扑绝缘体的微观模型，通过分析计算实现手性铰链通道，为在真实材料中发现受$C_4\boldsymbol{\tau}$保护的HOTI开辟了新途径。
中文摘要 AI 辅助
尽管高阶拓扑绝缘体（HOTIs）的研究已取得显著进展，但受手性$C_4\boldsymbol{\tau}$保护的HOTI在电子材料中仍未实现，其中$C_4\boldsymbol{\tau}$表示四重旋转对称性与时间反演对称性的乘积。我们表明，交替磁性（一种新近发现的共线磁性形式）为实现这一难以捉摸的相提供了新途径。具体而言，我们构建了一个微观模型，将三维拓扑绝缘体与Lieb晶格上的共线d波交替磁性相结合。通过分析和数值计算，我们证明该磁性使表面狄拉克锥发生位移并打开能隙，从而产生所需的手性铰链通道。最后，我们确定了有望实现该方案的材料类别。我们的研究结果确立了共线交替磁性作为本征手性高阶拓扑的实现途径，并为在真实材料中发现受$C_4\boldsymbol{\tau}$保护的HOTI开辟了新路径。
英文摘要
Despite significant progress in the study of higher-order topological insulators (HOTIs), the chiral $C_4\mathcal{T}$-protected HOTI has remained elusive in electronic materials, where $C_4\mathcal{T}$ denotes the product of a four-fold rotation and time-reversal symmetry. We show that altermagnetism, a recently discovered form of collinear magnetism, provides a new route to realize this elusive phase. Specifically, we construct a microscopic model that combines a three-dimensional topological insulator with a collinear $d$-wave altermagnet on a Lieb lattice. Through analytical and numerical calculations, we show that the magnetism shifts and gaps the surface Dirac cones to produce the desired chiral hinge channels. Finally, we identify promising material classes to realise our proposal. Our results establish collinear altermagnetism as a route to intrinsic chiral higher-order topology and open a new path toward the discovery of $C_4\mathcal{T}$-protected HOTIs in real materials.
