Electron spectrum, thermodynamics and transport in antiferromagnetic metals at low temperatures

TL;DR

This paper investigates electron spectra, thermodynamics, and transport in low-temperature antiferromagnetic metals, revealing Fermi-liquid behavior at very low temperatures and marginal Fermi liquid characteristics at higher temperatures, with suppressed Kondo effects.

Contribution

It provides a detailed analysis of spin-fluctuation effects on electron properties in 2D and 3D antiferromagnetic metals, including the impact of frustration and impurity scattering.

Findings

Fermi-liquid behavior at T<T* with T^3lnT specific heat contributions.

Marginal Fermi liquid behavior with TlnT specific heat and nearly T-linear resistivity at T>T*.

T-linear resistivity and TlnT thermoelectric power in 2D systems at low temperatures.

Abstract

Electron spectrum of 2D and 3D antiferromagnetic metals is calculated with account of spin-fluctuation corrections within perturbation theory in the s-f exchange model. Effects of the interaction of conduction electrons with spin waves in thermodynamic and transport properties are investigated. At lowest temperatures $T<T^{*}\sim (\Delta /E_F)T_N$ ($\Delta $ is the AFM splitting of the electron spectrum) a Fermi-liquid behavior takes place, and non-analytic T^3lnT-contributions to specific heat are present for D=3. At the same time, for T>T^{*}, in 2D and ``nested'' 3D systems the picture corresponds to a marginal Fermi liquid (TlnT-contributions to specific heat and nearly T-linear dependence of resistivity). Frustrations in the spin system in the 3D case are demonstrated to lead to similar results. The Kondo contributions to electronic properties are analyzed and demonstrated to be strongly suppressed. The incoherent contributions to transport properties in the presence of impurity scattering are considered. In particular, in the 2D case T-linear terms in resistivity are present up to T=0, and thermoelectric power demonstrates the anomalous T\lnT-dependence.