Low temperature resistivity in a nearly half-metallic ferromagnet

TL;DR

This paper analyzes how disorder and magnon interactions affect low-temperature electrical resistivity in nearly half-metallic ferromagnets, revealing specific temperature scaling behaviors.

Contribution

It provides an exact solution to the Boltzmann equation for resistivity due to magnon scattering in disordered half-metals, highlighting different temperature dependencies.

Findings

Resistivity scales as T^{1.5} or T^{2} depending on the density of states.

Derived temperature dependence of resistivity at low temperatures.

Discussed implications for doped perovskite manganites.

Abstract

We consider electron transport in a nearly half-metallic ferromagnet, in which the minority spin electrons close to the band edge at the Fermi energy are Anderson-localized due to disorder. For the case of spin-flip scattering of the conduction electrons due to the absorption and emission of magnons, the Boltzmann equation is exactly soluble to the linear order. From this solution we calculate the temperature dependence of the resistivity due to single magnon processes at sufficiently low temperature, namely $k_BT\ll D/L^2$, where $L$ is the Anderson localization length and $D$ is the magnon stiffness. And depending on the details of the minority spin density of states at the Fermi level, we find a $T^{1.5}$ or $T^{2}$ scaling behavior for resistivity. Relevance to the doped perovskite manganite systems is discussed.