Multi-Orbital Interactions and Spin Polarization in Single Rare-Earth Adatoms

TL;DR

This study employs orbital-resolved X-ray spectroscopy to quantify multi-orbital interactions and spin polarization in single rare-earth Nd adatoms, revealing detailed magnetic properties and validating the method for surface-adsorbed lanthanides.

Contribution

It introduces orbital-resolved X-ray spectroscopy as a reliable technique to analyze complex multi-orbital interactions and magnetic properties in rare-earth adatoms.

Findings

Quantified Coulomb integrals of Nd atoms on surfaces.

Identified magnetic moments of tens of μ_B at 5d orbitals.

Demonstrated magnetic coupling between 5d and 4f orbitals.

Abstract

Surface-adsorbed rare-earth nanostructures are ideal platforms to investigate the interplay between intra-atomic interactions and multi-orbital spin configurations. However, addressing these properties has posed severe experimental and theoretical challenges. Here, we use the orbital selectivity offered by X-ray absorption spectroscopy to quantify the Coulomb integrals of Nd atoms on conductive surfaces, as well as the variation of individual orbital occupation upon cluster nucleation. Using X-ray magnetic circular dichroism we identify magnetic moments of the order of \MK{few tens of}~$\mu_{\rm{B}}$ at the $5d$ orbitals and their magnetic coupling with the $4f$ spins. Our results validate orbital-resolved X-ray spectroscopy as a reliable method for quantifying complex multi-orbital interactions in surface-adsorbed lanthanides.