论文标题
超导双层中的杂质周围的状态
Bound states around impurities in a superconducting bilayer
论文作者
论文摘要
从理论上讲，我们研究超导双层中杂质的结合状态的外观。我们将注意力集中在$ S $波配对上，其中包括自由度层允许的非常规的奇数状态。利用数值平均场和分析$ t $ -matrix方法，我们调查了该模型中独立于动量的杂质潜力产生的界限。对于均匀的$ s $ - 波配对状态，仅针对破坏时间反转对称性的杂质。相比之下，对于奇数$ s $ - 波状态，所有杂质潜力通常都发现了约束状态，并属于六个不同的类别。该分类对于节点间隙仍然有效。从``超导健身''概念方面方便地理解了我们的结果，并显示了杂质的成对效应与正常状态带结构之间的相互作用。
We theoretically study the appearance of bound states around impurities in a superconducting bilayer. We focus our attention on $s$-wave pairing, which includes unconventional odd-parity states permitted by the layer degree of freedom. Utilizing numerical mean-field and analytical $T$-matrix methods, we survey the bound state spectrum produced by momentum-independent impurity potentials in this model. For even-parity $s$-wave pairing bound states are only found for impurities which break time-reversal symmetry. For odd-parity $s$-wave states, in contrast, bound states are generically found for all impurity potentials, and fall into six distinct categories. This categorization remains valid for nodal gaps. Our results are conveniently understood in terms of the ``superconducting fitness'' concept, and show an interplay between the pair-breaking effects of the impurity and the normal-state band structure.
