Pressure induced quantum critical point and non-Fermi-liquid behavior in BaVS3

The phase diagram of BaVS3 is studied under pressure using resistivity meas urements. The temperature of the metal to nonmagnetic Mott insulator transi tion decreases under pressure, and vanishes at the quantum critical point p (cr) = 20 kbar. We find two kinds of anomalous conducting states. The high- pressure metallic phase is a non-Fermi liquid described by Delta rho propor tional to T-n where n = 1.2-1.3 at 1 < T < 40 K. At p < p(cr), the transiti on is preceded by a wide precursor region with critically increasing resist ivity which we ascribe to the opening of a soft Coulomb gap.