Transition from tunneling regime to local point contact realized on Ba0.6K0.4Fe2As2 surface  

作　　者：侯兴元 揭云印 巩靖 沈冰 子海 李春红 任聪 单磊 

机构地区：[1]Beijing National Laboratory for Condensed Matter Physics, Institute of Physics, Chinese Academy of Sciences, Beijing 100190, China [2]School of Physical Sciences, University of Chinese Academy of Sciences, Beijing 100049, China [3]Collaborative Innovation Center of Quantum Matter, Beijing 100190, China

出　　处：《Chinese Physics B》2017年第6期373-377,共5页中国物理B（英文版）

基　　金：supported by the National Natural Science Foundation of China(Grant Nos.11574372 and 11322432);the“Strategic Priority Research Program(B)”of the Chinese Academy of Sciences(Grant No.XDB07020300)

摘　　要：Using scanning tunneling spectroscopy, we studied the transition from tunneling regime to local point contact on the iron-based superconductor Ba0.6K0.4Fe2As2. By gradually reducing the junction resistance, a series of spectra were obtained with the characteristics evolving from single-particle tunneling into Andreev reflection. The spectra can be well fitted to the modified Blonder–Tinkham–Klapwijk（BTK） model and exhibit significant changes of both spectral broadening and orbital selection due to the formation of point contact. The spatial resolution of the point contact was estimated to be several nanometers, providing a unique way to study the inhomogeneity of unconventional superconductors on such a scale.Using scanning tunneling spectroscopy, we studied the transition from tunneling regime to local point contact on the iron-based superconductor Ba0.6K0.4Fe2As2. By gradually reducing the junction resistance, a series of spectra were obtained with the characteristics evolving from single-particle tunneling into Andreev reflection. The spectra can be well fitted to the modified Blonder–Tinkham–Klapwijk（BTK） model and exhibit significant changes of both spectral broadening and orbital selection due to the formation of point contact. The spatial resolution of the point contact was estimated to be several nanometers, providing a unique way to study the inhomogeneity of unconventional superconductors on such a scale.

关 键 词：iron-based superconductor tunneling spectra point contact spectra 

分 类 号：O511.3[一般工业技术—材料科学与工程]