论文标题
2D拓扑模型中的边缘和角超导性
Edge and corner superconductivity in a 2D topological model
论文作者
论文摘要
我们考虑了Su-Schrieffer-Heeger模型的二维概括，该模型已知具有非平凡的拓扑结构。对于以单个参数为特征的该模型，跳高比$ 0 \ leq r \ leq 1 $，使用平均磁场理论研究了由有吸引力的$ u $ hubbard相互作用引起的不均匀超导阶段。我们通过分析和数值对角度表明，在具有开放界限的晶格中，根据填充而显示具有增强的超导顺序或边缘的超导顺序的相。对于半填充的有限样品，转角位点超导过渡温度可能比散装的温度大得多。因此，对于$ t_ {c，bulk} <t <t <t_ {c，corner} $产生了一种新颖的接近效应，其中转角站点在散装中创建了超导顺序的非零尾巴。我们表明，对于$ r $和$ u $值的范围，应该可以观察到这样的尾巴。
We consider a two-dimensional generalization of the Su-Schrieffer-Heeger model which is known to possess a non-trivial topological band structure. For this model, which is characterized by a single parameter, the hopping ratio $0 \leq r\leq 1$, the inhomogeneous superconducting phases induced by an attractive $U$ Hubbard interaction are studied using mean field theory. We show, analytically and by numerical diagonalization, that in lattices with open boundaries, phases with enhanced superconducting order on the corners or the edges can appear, depending on the filling. For finite samples at half filling, the corner site superconducting transition temperature can be much larger than that of the bulk. A novel proximity effect thus arises for $T_{c,bulk} < T<T_{c,corner}$, in which the corner site creates a nonzero tail of the superconducting order in the bulk. We show that such tails should be observable for a range of $r$ and $U$ values.
