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Title: Electronic Structure of the Metastable Epitaxial Rock-Salt SnSe { 111 } Topological Crystalline Insulator

Topological crystalline insulators have been recently predicted and observed in rock-salt structure SnSe {111} thin films. Previous studies have suggested that the Se-terminated surface of this thin film with hydrogen passivation has a reduced surface energy and is thus a preferred configuration. In this paper, synchrotron-based angle-resolved photoemission spectroscopy, along with density functional theory calculations, is used to demonstrate that a rock-salt SnSe {111} thin film epitaxially grown on Bi 2Se 3 has a stable Sn-terminated surface. These observations are supported by low-energy electron diffraction (LEED) intensity-voltage measurements and dynamical LEED calculations, which further show that the Sn-terminated SnSe {111} thin film has undergone a surface structural relaxation of the interlayer spacing between the Sn and Se atomic planes. In sharp contrast to the Se-terminated counterpart, the observed Dirac surface state in the Sn-terminated SnSe {111} thin film is shown to yield a high Fermi velocity, 0.50 x 10 6 m/s, which suggests a potential mechanism of engineering the Dirac surface state of topological materials by tuning the surface configuration.
 [1] ;  [2] ;  [3] ;  [4] ;  [5] ;  [6] ;  [7] ;  [8] ;  [2] ;  [2] ;  [2] ;  [2] ;  [4] ;  [4] ;  [5] ;  [8] ;  [8] ;  [2] ;  [6] ;  [4] more »;  [1] ;  [9] ;  [1] « less
  1. Columbia Univ., New York, NY (United States)
  2. Cornell Univ., Ithaca, NY (United States)
  3. Univ. of California, Santa Barbara, CA (United States)
  4. Chinese Academy of Sciences (CAS), Beijing (China)
  5. Renmin Univ. of China, Beijing (China)
  6. Univ. of New Hampshire, Durham, NH (United States)
  7. Brookhaven National Lab. (BNL), Upton, NY (United States)
  8. Univ. of Notre Dame, IN (United States)
  9. Cornell Univ., Ithaca, NY (United States); Univ. of Notre Dame, IN (United States)
Publication Date:
Report Number(s):
Journal ID: ISSN 2160-3308; R&D Project: 16083/16083; KC0403020
Grant/Contract Number:
FG02-04ER46157; SC0012704; 1433490; DMR-1400432; DMR-1120296; DMR-1408838; DMR-1506119; DMR-1006863; 11274381; 2015CB921300; 2013CB921700; 11474340; 11234014; XDB07000000
Published Article
Journal Name:
Physical Review. X
Additional Journal Information:
Journal Volume: 7; Journal Issue: 4; Journal ID: ISSN 2160-3308
American Physical Society
Research Org:
Columbia Univ., New York, NY (United States); Cornell Univ., Ithaca, NY (United States); Chinese Academy of Sciences (CAS), Beijing (China); Brookhaven National Lab. (BNL), Upton, NY (United States)
Sponsoring Org:
USDOE Office of Science (SC), Basic Energy Sciences (BES) (SC-22); National Science Foundation (NSF); National Natural Science Foundation of China (NNSFC); Ministry of Science and Technology of China; Chinese Academy of Sciences
Country of Publication:
United States
75 CONDENSED MATTER PHYSICS, SUPERCONDUCTIVITY AND SUPERFLUIDITY; electronic structure; first-principles calculations; surface & interfacial phenomena; surface states; topological materials
OSTI Identifier:
Alternate Identifier(s):
OSTI ID: 1407471