Influence of the electron–electron scattering on the kinetic effects in many‐valley semiconductors

The conductivity and magnetoresistance (MR) of a many‐valley semiconductor are calculated for the case when electron scattering on impurities and on the electrons of the same and of the other valleys is characterized by different coupling constants. It is shown that, with increasing anisotropy of the ellipsoidal energy surfaces, the contribution of the electron–electron scattering grows rapidly and MR decreases. The ratio of the coupling constants may be determined unambiguously through analysing the stress dependence of the conductivity and of MR in these semiconductors. The piezomagnetoresistance is shown to increase along with growing electron–electron scattering.