We extend an earlier analysis of the electric conductivity of field-induced spin-density waves by including the higher-order terms in $t_b$/$t_a$ where $t_a$ and $t_b$ are the electron-transfer integrals along the a and b axes, respectively. In the normal state the resulting conductivity tensor reproduces the result by Cooper et al. In the spin-density-wave states we predict an electric-field-dependent ${\sigma }_{\mathrm{xx}}$, but little electric field dependence for ${\sigma }_{\mathrm{xy}}$ and ${\sigma }_{\mathrm{yy}}$ associated with the Fröhlich conduction. We do not find the quantized Hall term within the single-gap approximation, although ${\sigma }_{\mathrm{xy}}$ varies almost stepwise with the external magnetic field at low temperatures. The results are compared with some of the experiments on Bechgaard salts.

• Received 25 April 1988

DOI:https://doi.org/10.1103/PhysRevB.39.616