Experimental Investigation of Electronic Structure of La(O,F)BiSe$_{2}$
Jun Ma1, Bin-Bin Fu1, Jun-Zhang Ma1, Ling-Yuan Kong1, Di Chen1, Ji-Feng Shao3, Chang-Jin Zhang3, Tian Qian1,2, Yu-Heng Zhang3, Hong Ding1,2**
1Beijing National Laboratory for Condensed Matter Physics, Institute of Physics, Chinese Academy of Sciences, Beijing 100190 2Collaborative Innovation Center of Quantum Matter, Beijing 100190 3High Magnetic field Laboratory of Chinese Academy of Sciences, University of Science and Technology of China, Hefei 230026
Abstract：La(O,F)BiSe$_{2}$ is a layered superconductor and has the same crystal structure with La(O,F)BiS$_{2}$. We investigate the electronic structure of La(O,F)BiSe$_{2}$ using the angle-resolved photoemission spectroscopy. Two electron-like Fermi surfaces around $X(\pi,0)$ are observed, corresponding to the electron doping of 0.23 per Bi site. We clearly resolve anisotropic band splitting along both ${\it \Gamma}$–$X$ and $M$–$X$ due to the cooperative effects of large spin-orbit coupling and interlayer coupling. Moreover, we observe an almost non-dispersive electronic state around $-$0.2 eV between the electron-like bands. This state vanishes after in-situ K evaporation, indicating that it could be the localized surface state caused by defects on the cleaved surface.
2016, Vol. 33 
