Many-body Green's function theory for thin ferromagnetic anisotropic Heisenberg films: treatment of the exchange anisotropy

TL;DR

This paper extends many-body Green's function theory to include exchange anisotropy in thin ferromagnetic films, allowing for more accurate modeling of their magnetic properties across various spin values and multilayer structures.

Contribution

The work introduces a formalism that incorporates exchange anisotropy into Green's function theory for thin ferromagnetic films, broadening its applicability.

Findings

Exchange anisotropy significantly influences magnetic reorientation.

The extended theory applies to arbitrary spin values and multilayer systems.

Comparison shows differences between exchange and single-ion anisotropy effects.

Abstract

The many-body Green's function theory developed in our previous work for treating the reorientation of the magnetization of thin ferromagnetic films is extended to include the exchange anisotropy. This leads to additional momentum dependencies which require some non-trivial changes in the formalism. The theory is developed for arbitrary spin values S and for multilayers. The effects of the exchange anisotropy and the single-ion anisotropy, which was treated in our earlier work, on the magnetic properties of thin ferromagnetic films are compared.