Varona S, Ortiz L, Viyuela O, Martin-Delgado M A
Departamento de Física Teórica, Universidad Complutense, 28040 Madrid, Spain.
J Phys Condens Matter. 2018 Oct 3;30(39):395602. doi: 10.1088/1361-648X/aadc71. Epub 2018 Aug 23.
We compute the topological phase diagram of 2D tetragonal superconductors for the only possible nodeless pairing channels compatible with that crystal symmetry. Subject to a Zeeman field and spin-orbit coupling, we demonstrate that these superconductors show surprising topological features: non-trivial high Chern numbers, massive edge states, and zero-energy modes out of high symmetry points, even though the edge states remain topologically protected. Interestingly, one of these pairing symmetries, [Formula: see text], has been proposed to describe materials such as water-intercalated sodium cobaltates, bilayer silicene or highly doped monolayer graphene, which opens the way for further applications of our results.
我们计算了二维四方超导体在与该晶体对称性兼容的唯一可能的无节点配对通道下的拓扑相图。在存在塞曼场和自旋轨道耦合的情况下,我们证明这些超导体展现出令人惊讶的拓扑特征:非平凡的高陈数、大量的边缘态以及在高对称点之外的零能模,尽管边缘态在拓扑上仍然受到保护。有趣的是,这些配对对称性之一,[公式:见正文],已被提议用于描述诸如水插层钠钴酸盐、双层硅烯或高度掺杂的单层石墨烯等材料,这为我们结果的进一步应用开辟了道路。