Atomically Smooth Ultrathin Films of Topological Insulator Sb_(2)Te_(3)  

作　　者：Guang Wang Xiegang Zhu Jing Wen Xi Chen Ke He Lili Wang Xucun Ma Ying Liu Xi Dai Zhong Fang Jinfeng Jia Qikun Xue 

机构地区：[1]Key Lab for Atomic,Molecular and Nanoscience,Department of Physics,Tsinghua University,Beijing 100084,China [2]Institute of Physics,the Chinese Academy of Sciences,Beijing 100190,China [3]Department of Physics,The Pennsylvania State University,Pennsylvania 16802,USA [4]Department of Physics,Shanghai Jiaotong University,Shanghai 200240,China [5]Department of Physics,Zhejiang University,Hangzhou,China

出　　处：《Nano Research》2010年第12期874-880,共7页纳米研究（英文版）

基　　金：The work is supported by the National Natural Science Foundation of China(NSFC);the National Basic Research Program of the Ministry of Science and Technology of China(MOST);Work at Pennsylvania State University is supported by the National Science Foundation(NSF)under Grant No.DMR 0908700.

摘　　要：The growth and characterization of single-crystalline thin films of topological insulators(TIs)is an important step towards their possible applications.Using in situ scanning tunneling microscopy(STM)and angle-resolved photoemission spectroscopy(ARPES),we show that moderately thick Sb_(2)Te_(3)films grown layer-by-layer by molecular beam epitaxy(MBE)on Si(111)are atomically smooth,single-crystalline,and intrinsically insulating.Furthermore,these films were found to exhibit a robust TI electronic structure with their Fermi energy lying within the energy gap of the bulk that intersects only the Dirac cone of the surface states.Depositing Cs in situ moves the Fermi energy of the Sb_(2)Te_(3)films without changing the electronic band structure,as predicted by theory.We found that the TI behavior is preserved in Sb_(2)Te_(3)films down to five quintuple layers(QLs).

关 键 词：Topological insulator electronic structure scanning tunneling microscopy angle-resolved photoemission spectroscopy molecular beam epitaxy 

分 类 号：X70[环境科学与工程—环境工程]