Sergii GRYTSIUK
The magnetocrystalline anisotropy is often attributed to the anisotropy of the orbital moments due to the on-site spin-orbit coupling. Here, we discover its multisite origin in B20 chiral magnets by employing first-principles calculations. In particular, we demonstrate that the spin-orbit coupling on neighboring atoms is the primary source of the orbital magnetism in B20 MnGe, while in B20 FeGe, it has a more vital on-site character. We calculate one- and two-site orbital susceptibility tensors and relate them to the corresponding one- and two-ion magnetocrystalline anisotropies. Furthermore, we find that such local and non-local spin-orbit effects, combined with pairwise spin-flip and orbit-orbit interaction, describe well the non-trivial magnetocrystalline anisotropy in B20 compounds.