Rare-Earth Atoms on Nb(110) as a Platform to Engineer Topological Superconductivity

来源：ACS Publications

Helical spin textures in one-dimensional magnetic chains on superconductors can enable topological superconductivity and host Majorana zero modes, independent of the presence of intrinsic spin–orbit coupling. Here, we show that gadolinium (Gd) adatoms, possessing large 4f magnetic moments when placed on a Nb(110) surface, establish indirect exchange interactions mediated by valence electrons, manifesting as Yu–Shiba–Rusinov states. By combining scanning tunneling microscopy and spectroscopy with density functional theory, we analyze the emergence of the Yu–Shiba–Rusinov states in single Gd atoms and Gd dimers and uncover the underlying magnetic interaction mechanisms. Based in these results we predict by means of spin-dynamics simulations the formation of stable chiral Néel-type spin-spiral configurations in Gd chains. These findings highlight rare-earth magnets as a promising platform for precisely tuning spin-spiral ground states, an essential prerequisite for the realization of topological superconductivity.