Non-Kondo mechanism for resistivity minimum in spin ice conduction systems

TL;DR

This paper proposes a non-Kondo mechanism explaining the resistivity minimum in spin ice conduction systems, emphasizing elastic scattering by local spin correlations influenced by geometrical frustration, supported by theoretical modeling and experimental comparisons.

Contribution

It introduces a novel non-Kondo mechanism for resistivity minima in spin ice systems, distinct from traditional Kondo physics, validated through cellular dynamical mean-field theory.

Findings

Resistivity shows a minimum due to elastic scattering by local spin correlations.

The mechanism explains peculiar temperature dependences in resistivity, specific heat, and magnetic susceptibility.

Theoretical results align with experimental data in metallic Ir pyrochlore oxides.

Abstract

We present a mechanism of resistivity minimum in conduction electron systems coupled with localized moments, which is distinguished from the Kondo effect. Instead of the spin-flip process in the Kondo effect, electrons are elastically scattered by local spin correlations which evolve in a particular way under geometrical frustration as decreasing temperature. This is demonstrated by the cellular dynamical mean-field theory for a spin-ice type Kondo lattice model on a pyrochlore lattice. Peculiar temperature dependences of the resistivity, specific heat, and magnetic susceptibility in the non-Kondo mechanism are compared with the experimental data in metallic Ir pyrochlore oxides.