Electron transport and energy relaxation in dilute magnetic alloys

TL;DR

This paper investigates how RKKY interactions among magnetic impurities influence electron relaxation and conductivity in metals, revealing non-monotonic temperature behaviors linked to magnetic impurity concentration and spin glass excitations.

Contribution

It introduces a detailed analysis of the combined effects of RKKY interaction and the Kondo effect on electron relaxation rates and conductivity in dilute magnetic alloys.

Findings

Electron relaxation rates show non-monotonic temperature dependence.

Maximum phase relaxation rate depends on impurity concentration.

Energy relaxation relates to magnetic impurity excitation spectrum.

Abstract

We consider the effect of the RKKY interaction between magnetic impurities on the electron relaxation rates in a normal metal. The interplay between the RKKY interaction and the Kondo effect may result in a non-monotonic temperature dependence of the electron momentum relaxation rate, which determines the Drude conductivity. The electron phase relaxation rate, which determines the magnitude of the weak localization correction to the resistivity, is also a non-monotonic function of temperature. For this function, we find the dependence of the position of its maximum on the concentration of magnetic impurities. We also relate the electron energy relaxation rate to the excitation spectrum of the system of magnetic impurities. The energy relaxation determines the distribution function for the out-of-equilibrium electrons. Measurement of the electron distribution function thus may provide information about the excitations in the spin glass phase.