Anisotropic transport in the spin-density-wave state of (TMTSF)(2)PF6

We have investigated the temperature dependence of the a and b' direction c onductivity in the spin-density wave phase of(TMTSF)(2)PF6 in the presence of a magnetic field (oriented perpendicular to the ab' plane) and hydrostat ic pressure. The band parameters are analyzed in the framework of the imper fect nesting model and the transfer integrals are deduced from the experime nts. The variation of the thermal gap, Delta(th)(B,p), is determined and it is compared to the theoretical expectations. Our results suggest that the strong influence of pressure and magnetic field on the a and b' direction t ransport can be described in terms of band parameters without introducing a nisotropy in the relaxation time. [S0163-1829(99)06431-0].