论文标题
界面和批量超导性在超导异质结构中具有增强的临界温度
Interface and bulk superconductivity in superconducting heterostructures with enhanced critical temperatures
论文作者
论文摘要
我们考虑通过在弱和强耦合方案中分别堆叠具有具有显着不同耦合强度的两个S波超导体的层获得的异质结构。选择弱和强耦合超导体的批量系统的临界温度相似。使用动态平均场理论方法，我们发现所有异质结构的超导临界温度无处不在，其中两个超导体之一的单层与另一个较厚的多层层交替。可以将两个不同的物理状态识别为较大层厚度的函数：（i）固有的不均匀性超导体，其特征在于两个孤立的散装超导体的性质，其中临界温度的增强局限于界面和（ii）散装超导管，具有增强的临界超导管，具有增强的临界温度，并具有增强的巨大温度。我们表征了这些与接近效应和配对相连的两个长度尺度之间的竞争之间的交叉表征。
We consider heterostructures obtained by stacking layers of two s-wave superconductors with significantly different coupling strengths, respectively in the weak- and strong-coupling regimes. The weak- and strong-coupling superconductors are chosen with similar critical temperatures for bulk systems. Using dynamical mean-field theory methods, we find an ubiquitous enhancement of the superconducting critical temperature for all the heterostructures where a single layer of one of the two superconductors is alternated with a thicker multilayer of the other. Two distinct physical regimes can be identified as a function of the thickness of the larger layer: (i) an inherently inhomogeneous superconductor characterized by the properties of the two isolated bulk superconductors where the enhancement of the critical temperature is confined to the interface and (ii) a bulk superconductor with an enhanced critical temperature extending to the whole heterostructure. We characterize the crossover between these regimes in terms of the competition between two length scales connected with the proximity effect and the pair coherence.
