Electron-phonon coupling of Fe-adatom electron states on MgO/Ag(100)

TL;DR

This study uses ab-initio calculations to analyze how the substrate and MgO coverage influence the electron-phonon coupling of Fe adatoms on MgO/Ag(100), revealing strong coupling at low MgO coverage and suppression at higher coverages.

Contribution

It provides new insights into the substrate and coverage dependence of electron-phonon interactions for Fe adatoms on MgO/Ag(100) using advanced many-body calculations.

Findings

Electron-phonon coupling is very strong for ≤ 1 layer of MgO.

Coupling is sharply suppressed for larger MgO coverages.

Interface electron states of Ag(100) significantly influence the coupling.

Abstract

We study the strength of the electron-phonon interaction on Fe single adatoms on MgO/Ag(100) based on many-body \textit{ab-initio} spin collinear calculations. In particular, we analyze the relative importance of the substrate and, among other results, we conclude that the interface electron state of Ag(100) plays a prominent role in determining the electron-phonon coupling of localized Fe electron states. The analysis of the hybridization of the adatom with the substrate reveals qualitative differences for even or odd coverages of MgO, affecting significantly the spectral structure and strength of the electron-phonon coupling. Our calculations indicate that the electron-phonon interaction is very strong for $\le$~1 layers of MgO, while it is sharply suppressed for larger coverages, a trend that is consistent with recent experimental findings.