Anomalously large g-factor of single atoms adsorbed on a metal substrate
Abstract
We performed magnetic field dependent inelastic scanning tunneling spectroscopy (ISTS) on individual Fe atoms adsorbed on different metal surfaces. ISTS reveals a magnetization excitation which is shifting linearly to higher energies in the magnetic field. The data is used to extract the magnetic anisotropies and the g-factors of the Fe atoms, as well as the lifetimes of the excitations. We find lifetimes of hundreds of femtoseconds limited by coupling to electron-hole pairs in the substrate and decreasing linearly upon application of the magnetic field. As expected, the magnetic anisotropy strongly depends on the substrate. Astoundingly, we find that the g-factor is g 3.1 for Ag(111) instead of the regular value of 2 which is observed for the Cu(111) substrate [1]. This very large g-shift 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. [4pt] [1] A. A. Khajetoorians et al., Phys. Rev. Lett. 106, 037205 (2011).
- Publication:
-
APS March Meeting Abstracts
- Pub Date:
- February 2012
- Bibcode:
- 2012APS..MAR.V1004W