| dc.description.abstract | Inspired by Onose et al,, who observed the thermal magnon Hall effect in pyrochlore
ferromagnetic structures, the present master Thesis investigates the same
effect of magnons in stable, rectangular, ferromagnetic and antiferromagnetic
skyrmionic lattices. Our analysis is based on a Hamiltonian which consists of
the following four terms: an exchange interaction, an easy axis anisotropy, the
Dzyaloshinskii-Moriya interaction and an external magnetic field. Transformations
on the initial Hamiltonian in order to obtain the non-interacting magnonic spin-wave
Hamiltonian, and the standard method of diagonalisation, allow us to numerically
compute the effective magnetic field that the magnons feel, which is essential ingredient
to compute the transverse thermal conductivity.
The results found for both ferromagnetic and antiferromagnetic lattices show the
presence of the Hall effect of magnons at low temperatures. Although a direct
comparison between ferromagnets and antiferromagnets is impossible, since they
differ in the size as well as in the number of skyrmions, we do compare the two
configurations to conclude that the antiferromagnetic structure exhibits a stronger
thermal Hall effect. | |
