I. Kezsmarki — Page 2

arXiv2000

Pressure Induced Quantum Critical Point and Non-Fermi-Liquid Behavior in BaVS3

The phase diagram of BaVS3 is studied under pressure using resistivity measurements. The temperature of the metal to nonmagnetic Mott insulator transition decreases under pressure, and vanishes at the quantum critical point p_cr=20kbar. We find two kinds of anomalous conducting states. The high-pressure metallic phase is a non-Fermi liquid described by Delta rho = T^n where n=1.2-1.3 at 1K < T < 60K. At p<p_cr, the transition is preceded by a wide precursor region with critically increasing resistivity which we ascribe to the opening of a soft Coulomb gap.

cond-mat.str-el↗

arXiv2000

Hall effect and conduction anisotropy in the organic conductor TMTSF2PF6

Long missing basic experiments in the normal phase of the anisotropic electron system of TMTSF2PF6 were performed. Both the Hall effect and the ab'-plane conduction anisotropy are directly addressing the unconventional electrical properties of this Bechgaard salt. We found that the dramatic reduction of the carrier density deduced from recent optical data is not reflected in an enhanced Hall-resistance. The pressure- and temperature dependence of the b'-direction resitivity reveal isotropic relaxation time and do not require explanations beyond the Fermi liquid theory. Our results allow a coherent-diffusive transition in the interchain carrier propagation, however the possible crossover to Luttinger liquid behavior is placed to an energy scale above room temperature.

cond-mat.str-el↗