FREQUENCY-DEPENDENCE OF THE HOPPING MAGNETOCONDUCTIVITY IN DISORDERED-SYSTEMS

We examine the frequency dependence of the hopping conductivity and ma gnetoconductivity (MC) in the framework of the effective-medium method . The calculation of the MC requires the inclusion of at least three-s ite hopping probabilities, which makes the studies considerably more d ifficult than those for H = 0. As a result, we find a simple relation between the ratio of the MC for omega not equal 0 to the static MC and the conductivity for H = 0. The ratio between the MC for omega not eq ual 0 and omega = 0 is independent of the magnetic field at low and me dium frequencies, where the critical hopping length does not considera bly deviate from its static value. Numerical calculations are performe d, which confirm the analytical results.