论文标题
Majorana角落模式和超导体/拓扑 - 绝缘体/超导体连接器中的扁平频带Majorana边缘模式
Majorana corner modes and flat-band Majorana edge modes in superconductor/topological-insulator/superconductor junctions
论文作者
论文摘要
最近，具有高阶拓扑的超导体激发了广泛的关注和研究兴趣。高阶拓扑超导体表现出非常规的散装对应关系，因此允许外来的低维边界模式，例如Majorana角和铰链模式。但是，在天然发生的材料中尚未发现高阶拓扑超导性。在这项工作中，我们研究了二维约瑟夫森连接处的高阶拓扑，该连接包括两个$ s $ - 波浪的超导体，这些超导体由拓扑绝缘子薄膜隔开。我们发现，可以通过施加磁场来实现零能量的主要角度模式，即高阶拓扑超导性的边界指纹。当平面内采地将其应用于系统时，超导连接中出现了两个角状态。此外，我们还发现了一个二维节点超导阶段，该阶段支持连接整体节点的平坦频段Majorana边缘模式。重要的是，我们证明零能量的主要角度模式在增加拓扑绝缘膜的厚度时是稳定的。
Recently, superconductors with higher-order topology have stimulated extensive attention and research interest. Higher-order topological superconductors exhibit unconventional bulk-boundary correspondence, thus allow exotic lower-dimensional boundary modes, such as Majorana corner and hinge modes. However, higher-order topological superconductivity has yet to be found in naturally occurring materials. In this work, we investigate higher-order topology in a two-dimensional Josephson junction comprised of two $s$-wave superconductors separated by a topological insulator thin film. We found that zero-energy Majorana corner modes, a boundary fingerprint of higher-order topological superconductivity, can be achieved by applying magnetic field. When an in-plane Zeeman field is applied to the system, two corner states appear in the superconducting junction. Furthermore, we also discover a two dimensional nodal superconducting phase which supports flat-band Majorana edge modes connecting the bulk nodes. Importantly, we demonstrate that zero-energy Majorana corner modes are stable when increasing the thickness of topological insulator thin film.
