Electronic properties and interfacial coupling in Pb islands on single-crystalline graphene  

作　　者：Jing-Peng Song Ang Li 宋靖鹏;李昂(State Key Laboratory of Functional Materials for Informatics,Shanghai Institute of Microsystem and Information Technology,Chinese Academy of Sciences,Shanghai 200050,China;University of Chinese Academy of Sciences,Beijing 100049 China)

机构地区：[1]State Key Laboratory of Functional Materials for Informatics,Shanghai Institute of Microsystem and Information Technology,Chinese Academy of Sciences,Shanghai 200050,China [2]University of Chinese Academy of Sciences,Beijing 100049 China

出　　处：《Chinese Physics B》2022年第3期517-520,共4页中国物理B（英文版）

基　　金：Project supported by the Science Foundation of the Science and Technology Commission of Shanghai Municipality, China (Grant No. 18ZR1447300)。

摘　　要：Introducing metal thin films on two-dimensional(2D) material may present a system to possess exotic properties due to reduced dimensionality and interfacial effects. We deposit Pb islands on single-crystalline graphene on a Ge(110)substrate and studied the nano-and atomic-scale structures and low-energy electronic excitations with scanning tunneling microscopy/spectroscopy(STM/STS). Robust quantum well states(QWSs) are observed in Pb(111) islands and their oscillation with film thickness reveals the isolation of free electrons in Pb from the graphene substrate. The spectroscopic characteristics of QWSs are consistent with the band structure of a free-standing Pb(111) film. The weak interface coupling is further evidenced by the absence of superconductivity in graphene in close proximity to the superconducting Pb islands.Accordingly, the Pb(111) islands on graphene/Ge(110) are free-standing in nature, showing very weak electronic coupling to the substrate.

关 键 词：scanning tunneling microscopy GRAPHENE quantum well states superconducting proximity effect 

分 类 号：O469[理学—凝聚态物理]