Real-space coexistence of the melted Mott state and superconductivity in Fe-substituted 1T-TaS ₂

We have performed high-resolution angle-resolved photoemission spectroscopy of layered chalcogenide 1T-Fe _xTa _1-xS ₂ which undergoes a superconducting transition in the nearly commensurate charge-density-wave phase (melted Mott phase). We found a single electron pocket at the Brillouin-zone center in the melted Mott phase, which is created by the backfolding of bands due to the superlattice potential of charge-density-wave. This electron pocket appears in the x region where the samples show superconductivity, and is destroyed by the Mott- and Anderson-gap opening. Present results suggest that the melted Mott state and the superconductivity coexist in real space, providing a new insight into the interplay between electron correlation, charge order, and superconductivity.