Anisotropic magnetoresistance in the hopping regime: Low frequencies and dc limit - art. no. 104204

The magnetic field dependence of the magnetoconductivity in the strongly lo calized regime is investigated at lowest frequencies, in the multiple hoppi ng regime and in the dc limit. It is found that the magnetoconductivity of isotropic three-dimensional samples is anisotropic. It depends on the angle between the electric and the magnetic field. A simple relationship between the longitudinal part of the magnetoconductivity and the transverse part o f the magnetoconductivity, valid for magnetic fields of any strength, is ob tained. It turns Out that the transverse part of the magnetoconductivity is always larger than the parallel part. As a function of the magnetic field the magnetoconductivity is a quadratic function for small magnetic fields, a nearly linear function for moderate magnetic fields, and saturates for hi gh magnetic fields. Its frequency dependence agrees with that of the conduc tivity in the range of frequencies in question.