Anomalously large g-factor of single atoms adsorbed on a metal substrate

TL;DR

This study investigates the magnetic properties of single Fe atoms on a Ag(111) surface, revealing an unusually large g-factor of 3.1 through inelastic tunneling spectroscopy and ab initio calculations, indicating complex electronic interactions.

Contribution

It demonstrates an anomalously large g-factor for single atoms on a metal surface, combining experimental ISTS measurements with theoretical ab initio analysis.

Findings

g-factor of 3.1 observed, significantly larger than the typical value of 2

Magnetization excitation lifetime approximately 400 femtoseconds

Linear decrease of excitation energy with applied magnetic field

Abstract

We have performed inelastic scanning tunneling spectroscopy (ISTS) on individual Fe atoms adsorbed on a Ag(111) surface. ISTS reveals a magnetization excitation with a lifetime of about 400 fsec which decreases linearly upon application of a magnetic field. Astoundingly, we find that the g-factor, which characterizes the shift in energy of the excitation in a magnetic field, is g = 3.1 instead of the regular value of 2. This enhancement can be understood when considering the complete electronic structure of both the Ag(111) surface state and the Fe atom, as shown by ab initio calculations of the magnetic susceptibility.