Evolution of the Fermi surface in superconductor PrO1-x Fx BiS2 (x=0.0,0.3, and 0.5) revealed by angle-resolved photoemission spectroscopy

We have investigated the electronic structure evolution with F doping in PrO1-xFxBiS2 (x=0.0,0.3,0.5) by means of angle-resolved photoemission spectroscopy. Undoped PrOBiS2 exhibits Fermi surface (FS) pockets around the X point which can be associated with electron doping due to the Pr3+/Pr4+ mixed valence. At x=0.3, the FS pockets are expanded, and their area is almost consistent with the F doping level. Interestingly, horizontal segments facing each other in the rectangular FS pockets lose their spectral weight. The partial suppression of the FS pockets suggests possible anisotropic charge fluctuations around x=0.3. At x=0.5, the FS area is much smaller than the expected value as commonly observed for CeO0.5F0.5BiS2 and NdO0.5F0.5BiS2. In addition, the highly depleted spectral weight at the FS pockets would be consistent with evident charge fluctuations driven by atomic disorder in the BiS2 network.