Observation of Coulomb Gap and Enhanced Superconducting Gap in Nano-Sized Pb Islands Grown on SrTiO3

作     者：Yonghao Yuan Xintong Wang Canli Song Lili Wang Ke He Xucun Ma Hong Yao Wei Li Qi-Kun Xue 袁永浩;王心童;宋灿立;王立莉;何珂;马旭村;姚宏;李渭;薛其坤

作者机构：State Key Laboratory of Low-Dimensional Quantum PhysicsDepartment of PhysicsTsinghua UniversityBeijing 100084 Frontier Science Center for Quantum InformationBeijing 100084 Institute for Advanced StudyTsinghua UniversityBeijing 100084 Beijing Academy of Quantum Information SciencesBeijing 100193 

出 版 物：《Chinese Physics Letters》 (中国物理快报（英文版）)

年 卷 期：2020年第37卷第1期

页      面：78-82页

核心收录：

学科分类：07[理学] 070205[理学-凝聚态物理] 0805[工学-材料科学与工程（可授工学、理学学位）] 0704[理学-天文学] 0702[理学-物理学] 

基　　金：the National Natural Science Foundation under Grant Nos.11674191 and 11825404 the National Key Program for S&T Research and Development under Grant No No.2016YFA0301002 the Beijing Advanced Innovation Center for Future Chip(ICFC).W.L.was also supported by Beijing Young Talents Plan 

主　　题：sized stronger phonon 

摘      要：We report high-resolution scanning tunneling microscopy(STM)study of nano-sized Pb islands grown on SrTiO3,where three distinct types of gaps with different energy scales are *** low temperature,we find that the superconducting gap(△s)in nano-sized Pb islands is significantly enhanced from the one in bulk Pb,while there is no essential change in superconducting transition temperature Tc,giving rise to a larger BCS ratio 2△s/kBTc^8.31 and implying stronger electron-phonon *** stronger coupling can originate from the interface electron-phonon interactions between Pb islands and *** the superconducting gap is totally suppressed under applied magnetic field,the Coulomb gap with apparent V-shape ***,the size of Coulomb gap(Ac)depends on the lateral size of Pb islands(R)with △c-1/R^035,indicating that quantum size effect can significantly influence electronic *** experimental results shall shed important light on the interplay among superconductivity,quantum size effect and correlations in nano-sized strong-coupling superconductors.