Evolution of metallic states from the Hubbard band in the two-dimensional Mott system BaCo1-xNixS2 - art. no. 075103

We report angle-resolved photoemission spectroscopy on the layered Mott sys tem BaCo1-xNixS2. (x = 0.18, 0.28) across the phase transition from the ant iferromagnetic insulator to anomalous metal. We found that the lower Hubbar d band in the insulating phase possesses a remnant of the Fermi surface in the metallic phase and gradually evolves into the metallic bands with carri er doping. We compare the experimental result with those of the high-T-c cu prates to discuss the absence of superconductivity in BaCo1-xNixS2.