Interplay between Yu-Shiba-Rusinov states and multiple Andreev reflections
Interplay between Yu-Shiba-Rusinov states and multiple Andreev reflections
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DOI：
10.1103/physrevb.101.235445
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发表时间：
2020-05
影响因子：
3.7
通讯作者：
A. Villas;Raffael L. Klees;Haonan Huang;C. Ast;G. Rastelli;W. Belzig;J. Cuevas
中科院分区：
文献类型：
--
作者：
A. Villas;Raffael L. Klees;Haonan Huang;C. Ast;G. Rastelli;W. Belzig;J. Cuevas
最近的扫描隧道显微镜实验超导表面上的单个磁性杂质的动机，我们在这里提出了一个全面的理论研究Yu-Shiba-Rusinov束缚态和（多）Andreev反射之间的相互作用。我们的理论是基于一个安德森模型与打破自旋简并和非平衡绿色的功能技术，使我们能够描述的电子输运通过磁杂质耦合到超导导线任意结的透明度相结合。使用这种组合，我们能够阐明不同的隧穿过程，给一个显着的贡献subgap运输。特别是，我们预测的发生大量的各种各样的Andreev反射介导的Yu-Shiba-Rusinov束缚态，明显不同于标准的Andreev过程中的非磁性系统。此外，我们提供了具体的指导方针，就如何实验确定的subgap功能源自这些隧道事件。总的来说，我们的工作提供了新的见解的作用的自旋自由度在Andreev输运物理。
Motivated by recent scanning tunneling microscopy experiments on single magnetic impurities on superconducting surfaces, we present here a comprehensive theoretical study of the interplay between Yu-Shiba-Rusinov bound states and (multiple) Andreev reflections. Our theory is based on a combination of an Anderson model with broken spin degeneracy and nonequilibrium Green's function techniques that allows us to describe the electronic transport through a magnetic impurity coupled to superconducting leads for arbitrary junction transparency. Using this combination we are able to elucidate the different tunneling processes that give a significant contribution to the subgap transport. In particular, we predict the occurrence of a large variety of Andreev reflections mediated by Yu-Shiba-Rusinov bound states that clearly differ from the standard Andreev processes in non-magnetic systems. Moreover, we provide concrete guidelines on how to experimentally identify the subgap features originating from these tunneling events. Overall, our work provides new insight into the role of the spin degree of freedom in Andreev transport physics.