Fermi Surface Folding and Surface Reconstruction in an Iron-Based Superconductor CaKFe<sub>4</sub>As<sub>4</sub>
ORAL
Abstract
High resolution angle resolved photoemission spectroscopy and scanning tunneling microscopy were carried on the CaKFe4As4 to study its electronic structure. CaKFe4As4 consists of parent compound CaFe2As2 and heavily hole doped KFe2As2 but with a high TC of 35K. We found three hole-like pockets at the Brillouin zone center and two electron-like pockets around the Brillouin zone corner. We also discovered a large hole pocket around the Brillouin zone corner which has the same size as the outmost hole pocket at the Brillouin center. Using scanning tunneling microscopy, we determine that there exists × reconstruction in CaKFe4As4, which will lead to the folding of the hole pocket from Brillouin zone center to Brillouin zone corner. The implication of these observations related to other iron-based superconductors will be discussed.
*This work is supported by the National Key Research and Development Program of China
(Grant No. 2016YFA0300300, 2017YFA0302900), the Strategic Priority Research Program
(B) of the Chinese Academy of Sciences (Grant No.XDB25000000), the National Natural
Science Foundation of China (Grant No. 11888101,11534007), and the Youth Innovation
Promotion Association of CAS (Grant No. 2017013).
–
Presenters
-
Yongqing Cai
- Beijing National Laboratory for Condensed Matter Physics, Institute of Physics, Chinese Academy of Sciences
- Chinese Academy of Sciences,Institute of Physics