Mottness in a doped organic superconductor

Abstract

We report the pressure study of a doped organic superconductor with Hall coefficient and conductivity measurements. We find that maximally enhanced superconductivity and a non-Fermi liquid appear around a certain pressure where mobile carriers increase critically, suggesting a possible quantum phase transition between strongly and weakly correlated regimes. Our description extends the conventional picture of a Mott metal-insulator transition at half filling to the case of a doped Mott insulator with tunable correlation.