Orbital-dependent electron correlation in LiFeAs revealed by angle-resolved photoemission spectroscopy

We report on the electronic structure of the 111-type iron pnictide superconductor LiFeAs as a function of temperature using angle-resolved photoemission spectroscopy. Below approximately 50 K, both the dyz hole band at the Z point and the dxz/yz electron band at the A point shift to a higher binding energy side. However, at the high-symmetry points Z,A,Γ, and M, the remaining bands are almost independent of temperature. One of the possible scenarios for these observations is that a strong, three-dimensional orbital-dependent correlation exists in the normal state of LiFeAs in relation to short-range spin fluctuations.