对介观尺寸非常规超导体的理论研究

Since the discovery of superconducitivity, it becomes one of the most remarkable phenomena in condensed matter physics, because of its huge potential of application and the great chanlege it raised to basic science. There are two types of superconductors, conventional superconductors and unconventional superconductors. The former one has s-wave pairing originated from electron-phonon coupling. The latter one usually has non-zero angular momentum pairing, such as p-wave and d-wave, which often has magnetic origin. In recent years, lots of attention are attracted by a special kind of unconventional superconductors, the chiral superconductor. These chiral superconductors have nontrivial topology and support many exotic excitations such as Majorana Fermions which has not only academical importance but also potential application to topological quantum computation. The study on these exotic exications are often related to mescoscopic materials. In our previous study, we find that the mesoscopic superconducting material may show different properties and physics as the bulk material. In this proposal, we plan to systematically study the properties of unconventional superconductors in small systems. We expect that our result can shed new light on our understanding of superconductivity and related exotic excitations.

超导电性自发现以来因为其巨大的应用潜力以及对理论提出的挑战而一直是凝聚态物理领域中最重要的现象之一。超导材料可以分为两类，常规超导体和非常规超导体。前者具有s-波配对，其超导微观机制源于电声相互作用。而后者一般具有非零角动量的配对，比如p-波和d-波配对等等，而其超导机理往往和磁性有关系。最近几年，人们对一类特殊的非常规超导体，手征超导体产生了兴趣。这类超导体具有非平庸的拓扑性质，而且这些材料中有可能存在一些奇异的激发，比如Majorana费米子等等。而Majorana费米子不仅具有学术上的重要意义，而且还可用于拓扑量子计算，因此收到了广泛关注。对这些激发的研究往往会涉及到介观尺寸的材料。而根据我们之前的研究，这种尺寸的材料会展现与大尺寸材料不同的物理。在本项目中，我们打算从理论上对介观系统的超导电性进行研究。我们期望我们的研究会增进我们对超导电性以及相关的奇异激发的了解。

超导电性自发现以来因为其巨大的应用潜力以及对理论提出的挑战而一直是凝聚态物理领域中最重要的现象之一。在本项目中，我们计划从理论上对介观系统的超导电性进行研究。在项目执行过程中，我们根据实际研究情况以及国际研究课题最新进展及发展趋势，就研究内容和方式上做了相应的调整。我们主要对介观超导电极与量子点耦合系统中的物理现象进行了理论研究，特别是里面近藤效应，超导，自旋轨道耦合等之间的相互竞逐与相互影响等。此外，我们还对多种凝聚态体系进行了理论探索。在本项目进行过程中，我们共发表SCI论文7篇，还有一篇已投稿的论文仍在审阅中。