Role of electron “lakes” in the negative magnetoresistance effect in the region of Mott hopping conductivity

Abstract

It is shown for doped and compensated germanium that the appearance of negative magnetoresistance under the conditions of Mott hopping conductivity may be due to the presence of a nonuniform spatial distribution of the electron density, the temperature at which the effect appears apparently being determined by the temperature at which the electron gas condenses into electron “lakes.” A “dead zone” effect was also observed in weak magnetic fields, the threshold field increasing with the nonuniformity of the electron distribution.