Observation of pseudogap in SnSe2 atomic layers grown on graphite  

作　　者：Ya-Hui Mao Huan Shan Jin-Rong Wu Ze-Jun Li Chang-Zheng Wu Xiao-Fang Zhai Ai-Di Zhao Bing Wang 

机构地区：[1]Hefei National Laboratory for Physical Sciences at the Microscale and Symergetic Innovation Center of Quantum Inforrnation and Quantum Physics,University of Science and Technology of China,Hefei 290026,China [2]School of Physical Science and Techrnology,ShanghaiTech University,Shanghai 201210,China

出　　处：《Frontiers of physics》2020年第4期113-120,共8页物理学前沿（英文版）

基　　金：We thank Prof.Tao Wu for helpful discus.sion.This work was supported by the National Key R&D Program of China(Grant Nos.2016YFA0200603 and 2017YFA0205004);the"Strategic Priority Research Program"of CAS(Grant No.XDB01020100);the National Natural Science Foundation of China(Grant Nos.91321309,21421063,and 21473174);the Funda-mental Research Funds for the Central Science Advances Universi-ties(Nos.WK2060190027 and WK2060190084);A.Z.acknowledges a fellowship from the Youth Innovation Promotion Association of CAS(No.2011322)。

摘　　要：Superconducting metal dichalcogenides(MDCs)present several similarities to the other layered SI1-perconductors like cuprates.The superconductivity in atomically thin MDCs has been demonstrated by recent experiments,however,the investigation of the superconductivity intertwined with other or-ders are scarce.Investigating the pseudogap in atomic layers of MDCs may help to understand the superconducting mechanism for these true two dimensional(2D)superconducting systemns.Herein we report a pseudogap opening in the tunneling spectra of thin layers of SnSe2 epitaxially grown on highly oriented pyrolytic graphite(HOPG)with scanning tunneling microscopy/spectroscopy(STM/STS).A significant V-shaped pseudogap was observed to open near the Fermi level(Er)in the sTS.And at elevated temperatures,the gap gradually evolves to a shallow dip.Our experimental observations provide direct evidence of a pseudogap state in the electron-doped SnSe2 atomic layers on the HOPG surface,which may stimulate further exploration of the mechanism of superconductivity at 2D limit in MDCs.

关 键 词：scanning tunneling microscopy PSEUDOGAP metal dichalcogenides SnSe2 van der Waals epitaxy 

分 类 号：O51[理学—低温物理]