Two Gaps in Semiconducting EuSbTe3 Studied by Angle-Resolved Photoemission Spectroscopy  

作　　者：樊聪聪 刘吉山 张凯莉 刘万领 卢祥乐 刘正太 吴东 刘中灏 沈大伟 尤立星 

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 [2]University of Chinese Academy of Sciences, Beijing 100049 [3]International Center for Quantum Materials, School of Physics, Peking University, Beijing 100871 [4]CAS Center for Excellence in Superconducting Electronics, Shanghai 200050

出　　处：《Chinese Physics Letters》2018年第7期81-84,共4页中国物理快报（英文版）

基　　金：Supported by the National Key R&D Program of China under Grant No 2016YFA0300204;the National Basic Research Program of China under Grant No 2015CB654901;the National Natural Science Foundation of China under Grant Nos 11574337,11227902,11474147 and 11704394;the Shanghai Sailing Program under Grant No 17YF1422900;the Award for Outstanding Member in Youth Innovation Promotion Association CAS

摘　　要：Using angle-resolved photoemission spectroscopy, we study the low-energy electronic structure of a layered ternary telluride EuSbTe3 semiconductor. It is found that the photoemission constant energy contours can be well described by the simple two-parameter（t（perp） and t（para）） tight-binding model based on the Te orbitals in square-net planes of EuSbTe3, suggesting its Te 5p orbitals dominated low-lying electronic structure, which is reminiscent of other rare-earth tritellurides. However, a possible charge-density-wave gap of 80 meV is found to persist in 300 K,which renders the unexpected semiconducting properties in EuSbTe3. Moreover, we reveal an extra band gap occurring around 200 meV below the Fermi level at low temperatures, which can be attributed to the interaction between the main and folded bands due to lattice scatterings. Our findings provide the first comprehensive understanding of the electronic structure of layered ternary tellurides, which lays the basis for future research on these compounds.Using angle-resolved photoemission spectroscopy, we study the low-energy electronic structure of a layered ternary telluride EuSbTe3 semiconductor. It is found that the photoemission constant energy contours can be well described by the simple two-parameter（t（perp） and t（para）） tight-binding model based on the Te orbitals in square-net planes of EuSbTe3, suggesting its Te 5p orbitals dominated low-lying electronic structure, which is reminiscent of other rare-earth tritellurides. However, a possible charge-density-wave gap of 80 meV is found to persist in 300 K,which renders the unexpected semiconducting properties in EuSbTe3. Moreover, we reveal an extra band gap occurring around 200 meV below the Fermi level at low temperatures, which can be attributed to the interaction between the main and folded bands due to lattice scatterings. Our findings provide the first comprehensive understanding of the electronic structure of layered ternary tellurides, which lays the basis for future research on these compounds.

分 类 号：O472[理学—半导体物理]