Observation of the anisotropic Dirac cone in the band dispersion of 112-structured iron-based superconductor Ca{sub 0.9}La{sub 0.1}FeAs{sub 2}
- State Key Laboratory of Functional Materials for Informatics, Shanghai Institute of Microsystem and Information Technology (SIMIT), Chinese Academy of Sciences, Shanghai 200050 (China)
- Department of Physics and Key Laboratory of MEMS of the Ministry of Education, Southeast University, Nanjing 211189 (China)
CaFeAs{sub 2} is a parent compound of recently discovered 112-type iron-based superconductors. It is predicted to be a staggered intercalation compound that naturally integrates both quantum spin Hall insulating and superconducting layers and an ideal system for the realization of Majorana modes. We performed a systematical angle-resolved photoemission spectroscopy and first-principles calculation study of the slightly electron-doped CaFeAs{sub 2}. We found that the zigzag As chain of 112-type iron-based superconductors play a considerable role in the low-energy electronic structure, resulting in the characteristic Dirac-cone like band dispersion as the prediction. Our experimental results further confirm that these Dirac cones only exist around the X but not Y points in the Brillouin zone, breaking the S{sub 4} symmetry at iron sites. Our findings present the compelling support to the theoretical prediction that the 112-type iron-based superconductors might host the topological nontrivial edge states. The slightly electron doped CaFeAs{sub 2} would provide us a unique opportunity to realize and explore Majorana fermion physics.
- OSTI ID:
- 22594378
- Journal Information:
- Applied Physics Letters, Vol. 109, Issue 4; Other Information: (c) 2016 Author(s); Country of input: International Atomic Energy Agency (IAEA); ISSN 0003-6951
- Country of Publication:
- United States
- Language:
- English
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Related Subjects
GENERAL PHYSICS
75 CONDENSED MATTER PHYSICS
SUPERCONDUCTIVITY AND SUPERFLUIDITY
ANISOTROPY
BRILLOUIN ZONES
CONES
DISPERSIONS
DOPED MATERIALS
ELECTRONIC STRUCTURE
ELECTRONS
IRON
LAYERS
MAJORANA FERMIONS
MAJORANA SPINORS
PHOTOELECTRON SPECTROSCOPY
PHOTOEMISSION
SPIN
SUPERCONDUCTORS
SYMMETRY
TOPOLOGY