二维铁电材料α-In_(2)Se_(3)表面分子束外延生长Pb纳米岛的STM研究  

STM Study of Pb Nano islands by Molecular Beam Epitaxy Growth on the Two-Dimensional Ferroelectricα-In_(2)Se_(3)

作　　者：刘姿[1,2] 胡昕 夏玉敏 蔡德胜 秦胜勇 LIU Zi;HU Xin;XIA Yumin;CAI Desheng;QIN Shengyong(International Center for Quantum Design of Functional Materials(ICQD),University of Science and Technology of China,Hefei,230026,China;Chinese Academy of Sciences Key Laboratory of Strongly Coupled Quantum Matter Physics,Department of Physics,University of Science and Technology of China,Hefei,230026,China)

机构地区：[1]中国科学技术大学,国际功能量子材料设计中心,安徽合肥230026 [2]中国科学技术大学物理系,中科院强耦合量子材料物理重点实验室,安徽合肥230026

出　　处：《低温物理学报》2022年第5期337-343,共7页Low Temperature Physical Letters

基　　金：国家重点基础研究发展计划(2017YFA0205004);国家自然科学基金资助项目(92165201,11634011);中央高校基本科研业务费专项资金(WK3430000003)资助的课题

摘　　要：铁电材料拥有自发电极化,不同的极化方向会对异质结的电子结构产生可逆的和非易失性的影响.本工作采用分子束外延技术在二维铁电材料α-In_(2)Se_(3)衬底上成功制备了Pb纳米岛构建Pb/α-In_(2)Se_(3)超导铁电异质结,并通过扫描隧道显微镜表征了其表面原子结构与电子结构.进一步的扫描隧道谱测量显示不同层厚Pb岛的量子阱态消失,并且我们在4.5K的温度下没有观察到超导能隙,表明铁电衬底会影响Pb岛的电子结构,甚至其超导特性.这些发现为理解铁电衬底对超导性的影响提供了参考,并为调控低维量子材料中的电子结构及超导性提供了新的思路.Ferroelectric materials possess spontaneous electrical polarization,which have reversible and nonvolatile effects on the electronic structure of the heterojunction.In this work,Pb nano islands are successfully fabricated on a two-dimensional ferroelectric a-In_(2)Se_(3)substrate by molecular beam epitaxy to construct a Pb/a-In_(2)Se_(3)superconductor-ferroelectric hetero junction,and its atomic structure and electronic structure are characterized by scanning tunneling microscopy.Further scanning tunneling spectroscopy measurements show that the quantum well states of the Pb nano islands disappear,and we do not observe superconducting energy gap at the temperature of as low as 4.5 K,indicating that the ferroelectric substrate affects the electronic structure and even the superconductivity of the Pb nano islands.These findings not only provide a reference for understanding the effect of ferroelectricity on superconductivity,but also offer a new platform to tune the electronic structure and superconductivity in low-dimensional quantum systems.

关 键 词：二维铁电 超导 扫描隧道显微镜 量子阱态 

分 类 号：TB34[一般工业技术—材料科学与工程]