Figure 5. Signatures of chirality-driven orbital magnetic moments in skyrmions.

(a) Net chirality-driven orbital moments (computed without SOC) and (b) topological orbital magnetization ratio (TOMR; equation (3); computed with SOC), for the skyrmionic structures shown in Fig. 3b–e, using the tight-binding model with 961 magnetic sites. The skyrmion radius can be varied experimentally by changing the applied magnetic field. The TOMR can be detected in an XMCD experiment by comparing the skyrmion lattice phase with a reference ferromagnetic phase. Two additional data points in a mark the chirality-driven orbital moments from DFT calculations for the largest skyrmions first described in ref. 29, for Pd/Fe/Ir(111) ( × ) and Pd₂/Fe/Ir(111) (+), which contain 73 Fe atoms.