A non-linear dissipative model of magnetism

Abstract

A new non-linear dissipative model of magnetism based on the laws of statistical physics is presented. The linear response theory is extended to pass from a quasi-static dynamics to the actual dynamics. The non-equilibrium dissipative dynamics explicitly takes into account the relaxation phenomena as well as the jumps over the energy barriers. The approach provides kinetic equations analogous to the phenomenological laws of transport appearing in the extended thermodynamics. The model holds from molecular magnets possessing plateaus to bulk magnetic materials. An energetic and entropic analysis along the lines initiated by Jaynes and Prigogine provides a deeper understanding of the non-equilibrium thermodynamics.

Lagrangian approach and dissipative magnetic systems

“…Our investigation can be grouped in the effort to understand dissipative mechanisms in magnets. So, a non-linear dissipative model for magnetic systems was discussed in [12]. On the relation between fluctuation-dissipation theorems and damping terms like that one occurring in the LLG was reported in [13].…”