• quantum field theory
• molecular dynamics simulations
• magnetic skyrmions
• condensed matter
• chiral molecular models
• chiral magnetism
• topological solitons

A magnetic skyrmion is a stable two dimensional nanoparticle describing a localized winding of the magnetization in certain magnetic materials. The mechanism responsible for stabilizing magnetic skyrmions, is due to the Dzyaloshinskii–Moriya (DM) interaction. Such additional term in the Heisenberg Hamiltonian describing ferromagnets, originates from the inversion symmetry breaking, typical of chiral magnets, and microscopically from the spin-orbit coupling. In this thesis, the chiral model for magnetic skyrmions in the Ginzburg Landau mean field approximation, is studied. An extended three-dimensional chiral model is proposed, analytical and numerical computations are performed. In this new model, two solitonic solutions within the unit topological sector were found: one corresponds to the stable 3D magnetic skyrmion and the other unstable one refers to the so-called "magnetic sphaleron", a saddle-point of the energy functional. Finally, the existence of a sphaleron solution for the chiral model of magnetic hopfions, was suggested.
The last part of the thesis is a report about the research's activity in molecular dynamics simulations of a chiral molecular model, that the candidate conduced at Princeton University within the Prof. Car's group.