Orbital-resolved single atom magnetism measured with X-ray absorption spectroscopy

TL;DR

This study uses orbital-resolved X-ray absorption spectroscopy to investigate the magnetism of surface-supported lanthanide atoms, revealing their electronic configurations and charge transfer mechanisms at the quantum level.

Contribution

It introduces a method to analyze the orbital-specific magnetism of lanthanide atoms on surfaces, combining spectroscopy with theoretical calculations.

Findings

Revealed valence electron occupation and magnetism of Gd and Ho atoms.

Identified a charge transfer mechanism leading to an unconventional singly ionized state.

Demonstrated the role of valence electrons in quantum nanostructure magnetism.

Abstract

Lanthanide atoms and molecules are promising candidates for atomic data storage and quantum logic due to the long magnetic lifetime of their electron quantum states. Accessing these states through electrical transport requires the engineering of their electronic configuration down to the level of individual atomic orbitals. Here, we address the magnetism of surface-supported lanthanide atoms, clusters, and films with orbital selectivity using X-ray absorption spectroscopy and magnetic circular dichroism. We exploit the selection rules of electric dipole transitions to reveal the occupation and magnetism of the valence electrons of Gd and Ho deposited on MgO/Ag(100). Comparing our results with multiplet calculations and density functional theory, we identify a charge transfer mechanism that leaves the lanthanide species in an unconventional singly ionized configuration. Our approach allows determining the role of valence electrons on the quantum level structure of lanthanide-based nanostructures.