Electron spectrum, thermodynamics, and transport in antiferromagnetic metals 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.