Ideas by S.V. Vonsovsky and Modern Model Treatment of Magnetism

TL;DR

This paper reviews the foundational and modern theoretical models of magnetism, highlighting their development, connections, and applications to complex materials like heavy fermion systems and Kondo lattices.

Contribution

It provides a comprehensive comparison of classical models with modern approaches, including exotic quasiparticles and their relevance to complex magnetic materials.

Findings

Connections between various many-electron models are elucidated.

Modern approaches incorporate slave-boson and slave-fermion techniques.

Descriptions of heavy fermion and non-Fermi-liquid systems are discussed.

Abstract

A review of fundamental works by Shubin and Vonsovsky on the formulation of the polar and s-d(f) exchange models is given. Their ideas are compared with subsequent developments in the theory of magnetism in d- and f-metals and their compounds. Modern approaches including different slave-boson and slave-fermion representations, formation of exotic quasiparticles etc. are discussed. Internal connections between various many-electron models (the Heisenberg, Hubbard, t-J, Anderson Hamiltonians) are presented. Description of anomalous rare-earth and actinide compounds (Kondo lattices, systems with heavy fermions and non-Fermi-liquid behavior) within the framework of the s-d(f) exchange model and related models is considered.