点接触技术在拓扑材料研究中的应用

点接触实验方法最早被用于研究固体材料中的元激发,后来发展到研究超导/普通金属界面上的Andreev反射现象,并利用这种现象探测超导序参量.随着拓扑材料以及拓扑超导领域研究的兴起,点接触实验方法在该领域也发挥了重要的作用.最近几年,点接触实验方法被用于在多种拓扑半金属材料表面诱导并探测超导信号,使其应用范围得到了进一步拓展.本文简要介绍了点接触的基本原理、利用点接触探测样品超导性质的方法以及点接触技术本身的发展,简单回顾了点接触在拓扑超导候选材料中的研究,最后介绍了点接触针尖诱导超导现象的发现以及进展.

Applications of point-contact spectroscopy in the study of topological materials

The point-contact spectroscopy was first used to study the elementary excitation in solid materials.Then it is widely used to probe the superconducting order parameters when Andreev reflection occurs at the superconductor/normal metal interfaces.With the development of topological materials and topological superconducting materials,it has also played an important role in the detection of the possible topological superconducting order parameters.Especially in recent years,the so-called tip-induced superconductivity has been detected on the surface of various topological semimetals by point-contact,which adds a new application scope to this classical experimental method.In this review,we try to introduce its basic principles and the development,as well as the applications in some fields.Then some respective studies of the topological superconductor candidates and the recently discovered tip-induced superconductivity by pointcontact in various topological materials are also briefly reviewed.