Real-space coexistence of the melted Mott state and superconductivity in Fe-substituted 1T-TaS2

Phys Rev Lett. 2012 Oct 26;109(17):176403. doi: 10.1103/PhysRevLett.109.176403. Epub 2012 Oct 23.

Abstract

We have performed high-resolution angle-resolved photoemission spectroscopy of layered chalcogenide 1T-Fe(x)Ta(1-x)S(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.