Atomic scale electronic structure of the ferromagnetic semiconductor Cr2Ge2Te6  

作　　者：Zhenqi Hao Haiwei Li Shunhong Zhang Xintong Li Gaoting Lin Xuan Luo Yuping Sun Zheng Liu Yayu Wang 

机构地区：[1]State Key Laboratory of Low Dimensional Quantum Physics,Department of Physics,Tsinghua University,Beijing 100084,China [2]Institute for Advanced Study,Tsinghua University,Beijing 100084,China [3]Key Laboratory of Materials Physics,Institute of Solid State Physics,Chinese Academy of Sciences,Hefei 230031,China [4]University of Sdence and Technology of China,Hefei 230026,China e High Magnetic Field Laboratory,Chinese Academy of Sciences,Hefei 230031,China [5]High Magnetic Field Laboratory,Chinese Academy of Sdences,Hefei 230031,China [6]Collaborative Innovation Centre of Advanced Microstructures,Nanjing University,Nanjing 210093,Chinag [7]Collaborative Innovation Center of Quantum Matter,Beijing 100084,China

出　　处：《Science Bulletin》2018年第13期825-830,共6页科学通报（英文版）

基　　金：supported by the Basic Science Center Project of NSFC(51788104);the MOST of China(2015CB921000);the support from Tsinghua University Initiative Scientific Research Program and NSFC(11774196);S.H.Z.is supported by the National Postdoctoral Program for Innovative Talents of China(BX201600091);the China Postdoctoral Science Foundation(2017M610858);the support of the National Key Research and Development Program(2016YFA0300404);NSFC Grant(11674326);the Joint Funds of NSFC and the Chinese Academy of Sciences’Large-Scale Scientific Facility(U1432139);supported in part by the Beijing Advanced Innovation Center for Future Chip(ICFC)

摘　　要：Cr_2Ge_2Te_6is an intrinsic ferromagnetic semiconductor with van der Waals type layered structure,thus represents a promising material for novel electronic and spintronic devices.Here we combine scanning tunneling microscopy and first-principles calculations to investigate the electronic structure of Cr_2Ge_2Te_6.Tunneling spectroscopy reveals a surprising large energy level shift and change of energy gap size across the ferromagnetic to paramagnetic phase transition,as well as a peculiar double-peak electronic state on the Cr-site defect.These features can be quantitatively explained by density functional theory calculations,which uncover a close relationship between the electronic structure and magnetic order.These findings shed important new lights on the microscopic electronic structure and origin of magnetic order in Cr_2Ge_2Te_6.Cr2Ge2Te6 is an intrinsic ferromagnetic semiconductor with van der Waals type layered structure, thus represents a promising material for novel electronic and spintronic devices. Here we combine scanning tunneling microscopy and first-principles calculations to investigate the electronic structure of Cr2Ge2Te6. Tunneling spectroscopy reveals a surprising large energy level shift and change of energy gap size across the ferromagnetic to paramagnetic phase transition, as well as a peculiar double-peak electronic state on the Cr-site defect. These features can be quantitatively explained by density functional theory calculations, which uncover a close relationship between the electronic structure and magnetic order. These findings shed important new lights on the microscopic electronic structure and origin of magnetic order in Cr2Ge2Te6.

关 键 词：Ferromagnetic semiconductor Electronic structure Scanning tunneling microscopy Density functional theory 

分 类 号：O472[理学—半导体物理]