Theory of electrical resistivity in an interacting two-carrier system: application to (SN)Xand (SNBry)X

Abstract

Electrical resistivity of an interacting two-carrier system has been investigated by using the coupled Boltzmann equation. An exact formula for the resistivity due to carrier-carrier scattering is derived under a plausible angular dependence of the distribution function. This formula indicates that the interband carrier-carrier normal scattering acts so as to attenuate the relative motion of the two types of carriers, while the intraband carrier-carrier normal scattering acts only so as to renormalise the masses of two types of carriers. It is also shown that the centre-of-mass motion of the two types of carriers cannot be attenuated in the absence of carrier-carrier Umklapp scattering and other scattering mechanisms such as carrier-phonon scattering. Moreover, in order to consider both carrier-carrier and carrier-phonon scattering mechanisms simultaneously, an optimum formula for the resistivity is also given and applied to the case of (SN)x and (SNBry)x whose Fermi surface consist of highly anisotropic electron and hole pockets. The observed behaviour in the magnitude and the temperature dependence of the resistivity along the chain axis of these materials is satisfactorily explained by the calculated results.