A magnetic helix arises in chiral magnets with a wavelength set by the spin-orbit coupling. We show that the helimagnetic order is a nanoscale analog to liquid crystals, exhibiting topological structures and domain walls that are distinctly different from classical magnets. Using magnetic force microscopy and micromagnetic simulations, we demonstrate that - similar to cholesteric liquid crystals - three fundamental types of domain walls are realized in the helimagnet FeGe. We reveal the micromagnetic wall structure and show that they can carry a finite skyrmion charge, permitting coupling to spin currents and contributions to a topological Hall effect. Our study establishes a new class of magnetic nano-objects with non-trivial topology, opening the door to innovative device concepts based on helimagnetic domain walls.
@article{arxiv.1704.06288,
title = {Topological domain walls in helimagnets},
author = {P. Schoenherr and J. Müller and L. Köhler and A. Rosch and N. Kanazawa and Y. Tokura and M. Garst and D. Meier},
journal= {arXiv preprint arXiv:1704.06288},
year = {2024}
}