Manifestation of spin-charge fluctuations in the spectral and thermodynamic properties of quasi-two-dimensional rare-earth intermetallic compounds

Abstract

In the framework of the modified periodic Anderson model with exchange interaction in the subsystem of localized states, it is shown that spin-charge fluctuations in quasi-two-dimensional intermetallic compounds with rare-earth ions in the mixed valence state significantly affect both the spectrum of magnetic excitations and the conditions at which the antiferromagnetic phase is realized. The spectral characteristics of the phase were obtained by the method of the diagram technique for Hubbard operators in the one-loop approximation, which allows to account for the spin-charge fluctuation contributions to the components of the mass and the force operators. The developed theory allowed to quantitatively describe the pressure dependence of the Néel temperature observed in a quasi-two-dimensional antiferromagnetic heavy-fermion intermetallic compound CeRhIn5.