NONLINEAR HALL-EFFECT IN THE FIELD-INDUCED SPIN-DENSITY-WAVE STATES OF (TMTSF)2PF6

The resistivity along the conducting chains, rho(xx), and the Hall res istivity rho(xy) are investigated as a function of the electric field in the magnetic-field-induced spin-density wave (FISDW) states of (TMT SF)2PF6 under hydrostatic pressure. Both resistivities decrease with i ncreasing electric field above the same well-defined threshold electri c field in the order of 100 muV/cm. We interpret the nonlinearity by t he depinning and sliding of the FISDW. The nonlinearity in rho(xy), is much stronger than in rho(xx) what we attribute to an unusually stron g coupling between the FISDW and single-particle excitations.