论文标题
单层和几层石墨烯的超导性：II。拓扑边缘状态和Chern数字
Superconductivity in monolayer and few-layer graphene: II. Topological edge states and Chern numbers
论文作者
论文摘要
我们研究了超导态（SC）单层，双层和三层石墨烯中电子边缘状态的出现，用于旋转单链和自旋 - 三角形SC订单参数。我们主要集中在间隙的手性$ p+ip'$ - 和$ d+id'$ - 波浪sc状态，这些状态显示了非零的chern号码和相应数量的边缘状态。对于$ p+ip'$ - 波状态，在调整化学势和SC顺序参数幅度时，我们会观察到一个丰富的Chern相图，这在很大程度上取决于层的数量及其堆叠，并且也通过Trigonal Warping进行了修改。在较小的参数值下，我们观察到一个区域，其Chern号是菱形堆积石墨烯所独有的，并且与层数无关。我们的结果不仅可以按照预期的是SC顺序参数绕组来理解，而且还可以从正常状态谱带结构中理解。该观察结果确定了正常状态特征对于理解SC石墨烯系统中拓扑的重要性。
We study the emergence of electronic edge states in superconducting (SC) monolayer, bilayer, and trilayer graphene for both spin-singlet and spin-triplet SC order parameters. We focus mostly on the gapped chiral $p+ip'$- and $d+id'$-wave SC states that show a non-zero Chern number and a corresponding number of edge states. For the $p+ip'$-wave state, we observe a rich Chern phase diagram when tuning the chemical potential and the SC order parameter amplitudes, which depends strongly on the number of layers and their stacking, and is also modified by trigonal warping. At small parameter values we observe a region whose Chern number is unique to rhombohedrally stacked graphene, and is independent of the number of layers. Our results can be understood in relation not only to the SC order parameter winding as expected, but also to the normal state band structure. This observation establishes the importance of the normal state characteristics for understanding the topology in SC graphene systems.
