Open AccessStudies of scanning tunneling spectroscopy on iron-based superconductors
Author(s) -
Qing Gu,
Siyuan Wan,
Huan Yang,
Hao Wen
Publication year - 2018
Publication title -
wuli xuebao
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.199
H-Index - 47
ISSN - 1000-3290
DOI - 10.7498/aps.67.20181818
Subject(s) - superconductivity , pairing , scanning tunneling microscope , scanning tunneling spectroscopy , condensed matter physics , fermi surface , physics , electron pair , high temperature superconductivity , electronic structure , topology (electrical circuits) , electron , materials science , quantum mechanics , mathematics , combinatorics
Since the discovery of iron-based superconductors in 2008, it has been a hot topic to research the pairing mechanism of superconductivity. Scanning tunneling microscopy (STM) can be used to detect the electronic information in nano-scale, hence, it is an important tool to do research on superconductivity. In recent 10 years, many valuable works have been carried out by STM in iron-based superconductors. In this paper, we try to make a brief introduction of the STM works in iron-based superconductors. Since the iron-based superconductors have multiple bands and superconducting gaps, the Fermi surface topology can change significantly among different materials. There are some evidences to prove a nodeless s-wave pairing in the optimally-doped iron-based superconductors with both electron and hole pockets by STM experiments. Furthermore, it has been demonstrated that FeSe-based materials with only electron pockets also have a sign-change order parameter, which provides a robust evidence for the unified picture of the electron pairing in iron-based superconductors. Besides, STM experiments provide fruitful information about the novel electronic properties including the electronic nematicity, shallow band effect, and possible topological superconductivity. Finally, we also give perspectives about the STM studies in iron based superconductors.