FORMATION AND STABILITY OF MAGNETIC HOPFIONS IN CHIRAL MAGNET

Work package:
Topological spin textures play a central role in modern magnetism. Their unique properties have attracted significant attention for both fundamental research and spintronic applications. To date, the main focus of the community so far has been on topological magnetization structures in two-dimension (2D), such as domain walls, vortices, and skyrmions. Theory predicts that we could form three-dimensional (3D) topological solitons, magnetic hopfions, if the two ends of a skyrmion are connected. Despite extensive research in recent years, direct observations of hopfions in crystals remained for a long time an unsolved problem. A breakthrough occurred in 2023 when scientists created and observed a stable hopfion in a solid [1]. Thanks to their intricate texture and three-dimensionality, hopfions may lead to a new generation of high-density, energy-efficient computing and memory devices, for example, supervised learning with 3D solitons. From a fundamental perspective, hopfions open a novel research avenue called 3D topological magnetism. The goal of the internship is to exploit the formation mechanism of hopfions in chiral magnets. This will be done by developing a multiscale approach that combines ab initio theory with atomistic spin models. The stability of hopfions will be investigated using the geodesic nudged elastic band method. Finally, we will employ high throughput first-principles calculations to predict novel materials capable of hosting magnetic hopfions.