Effect of Magnon Drag on Electron Mass and Mobility

Abstract

We consider an idealized model of a ferromagnetic metal where the conduction electrons of the $s$ band interact via an exchange interaction with a system of spins represented by a Heisenberg Hamiltonian. Using double-time Green's functions, the effective mass and resistivity are evaluated to second order in the coupling of electrons to the spin system, while the spin magnetization is given by the self-consistent approximation of Bogoliubov and Tyablikov. The resistivity shows a sharp change in slope at the critical temperature that agrees qualitatively with the experimental results for gadolinium.