Adsorption-induced constraint on delocalization of electron states in an Au chain on NiAl(110)

TL;DR

This study uses density functional theory to investigate how CO adsorption on a gold chain on NiAl(110) surface constrains electron delocalization, confirming experimental observations of localized resonance states.

Contribution

It provides a detailed theoretical analysis of how molecular adsorption affects electron resonance states in a metal chain, revealing the mechanism behind localization.

Findings

CO adsorption breaks degeneracy of resonance states

Disrupts electron delocalization in the Au chain

Confirms experimental STM/STS observations

Abstract

We have carried out a density functional study of the localized constraint on the delocalized, unoccupied resonance states in a mono atomic Au chain on a NiAl(110) surface by adsorption of a CO molecule on one of the adatoms in the chain. This constraint was observed recently by scanning tunnelling microscopy and spectroscopy. The repulsive interaction of the occupied 5${\sigma}$ molecular state with the unoccupied, resonance state in a Au adatom in the chain is found to break the degeneracy of the Au adatom-induced resonance states and to disrupt their delocalization in the chain.