Non-Fermi-liquid behavior in the Kondo lattices induced by peculiarities of magnetic ordering and spin dynamics

TL;DR

This paper investigates how peculiar magnetic ordering and spin dynamics in Kondo lattices induce non-Fermi-liquid behavior, explaining experimental observations in heavy-fermion systems and predicting measurable physical properties.

Contribution

It introduces a scaling approach considering singularities in spin excitation spectra, revealing conditions for NFL behavior in complex magnetic structures and simple antiferromagnets.

Findings

NFL behavior occurs between two critical coupling constants in complex magnetic structures.

Different NFL-like states can arise in simple antiferromagnets with magnon damping.

Predictions made for specific heat, resistivity, and magnetic susceptibility behaviors.

Abstract

A scaling consideration of the Kondo lattices is performed with account of singularities in the spin excitation spectral function. It is shown that a non-Fermi-liquid (NFL) behavior between two critical values of the bare $s-f$ coupling constant occurs naturally for complicated magnetic structures with several magnon branches. This may explain the fact that a NFL behavior takes place often in the heavy-fermion systems with peculiar spin dynamics. Another kind of a NFL-like state (with different critical exponents) can occur for simple antiferromagnets with account of magnon damping, and for paramagnets, especially with two-dimensional character of spin fluctuations. The mechanisms proposed lead to some predictions about behavior of specific heat, resistivity, magnetic susceptibility, and anisotropy parameter, which can be verified experimentally.