Midway evaluation in Chemistry - Moritz Sallermann

Title of thesis: Simulation studies of Hopfions using atomistic spin models

Doctoral candidate: Moritz Sallermann

Doctoral committee: 
Dr. Hannes Jónsson, Professor at the Faculty of Physical Sciences, University of Iceland
Dr. Pavel Bessarab, Researcher at the Science Institute, University of Iceland
Dr. Nikolai Kiselev, Staff Scientist at the Forschungszentrum Jülich, Germany

Abstract

In this Ph.D project three-dimensional, topologically non-trivial, magnetic structures – called Hopfions – are investigated numerically. Due to their three-dimensional nature, Hopfions are promising candidates for novel, three-dimensional spintronics devices. Currently proposed device designs are limited by the use of inherently two-dimensional structures – such as the celebrated Skyrmions – as information carriers. If Hopfions were used instead, these limitations could potentially be overcome. Unfortunately, Hopfions have, as of yet, not been observed in magnetic, solid materials. Therefore, simulation studies are pivotal to guide the experimental search. Previous theoretical studies have identified frustrated magnets as promising candidates. In the project, energy barriers and collapse mechanisms for Hopfions in these systems are investigated.