Localized spin-orbit polaron in magnetic Weyl semimetal Co₃Sn₂S₂

The transition metal based kagome lattice compounds have merged as a novel platform for exploring the physics of geometric frustration, correlation and magnetism, and the topological behaviors of quantum electronic states. The kagome lattice Co₃Sn₂S₂ exhibits the quintessential topological phenomena of a magnetic Weyl semimetal such as chiral anomaly and Fermi-arc surface states. Probing its magnetic properties is crucial for understanding this correlated topological state. Here, using spin-polarized scanning tunneling microscopy/spectroscopy (STM/S) and non-contact atomic force microscopy (nc-AFM) combined with first-principle calculations, we report the discovery of localized spin-orbit polarons (SOPs) with three-fold rotation symmetry nucleated around single S-vacancies in Co₃Sn₂S₂. The SOPs carry a magnetic moment and a large diamagnetic orbital magnetization of a possible topological origin relating to the diamagnetic circulating current around the S-vacancy. Appreciable magneto-elastic coupling of the SOP is detected by nc-AFM and STM. Our findings suggest the SOPs can enhance magnetism and more robust time-reversal-symmetry-breaking topological phenomena. Controlled engineering of the SOPs may pave the way toward practical applications in functional quantum devices.