Evaluation of conduction eigenchannels of an adatom probed by an STM tip

TL;DR

This paper investigates how the conductance eigenchannels of a single atom on a surface, probed by an STM tip, reflect changes in the atom's local electronic structure, revealing nonmonotonic transmission behaviors for open shell atoms.

Contribution

It provides first-principles evidence that eigenchannel transmission probabilities encode local density of states modifications due to STM tip interaction.

Findings

Eigenchannel transmissions reveal local density of states changes.

Nonmonotonic transmission behavior observed for open shell atoms.

Density functional theory confirms the relationship between conductance and atomic electronic structure.

Abstract

Ballistic conductance through a single atom adsorbed on a metallic surface and probed by a scanning tunneling microscope (STM) tip can be decomposed into eigenchannel contributions, which can be potentially obtained from shot noise measurements. Our density functional theory calculations provide evidence that transmission probabilities of these eigenchannels encode information on the modifications of the adatom's local density of states caused by its interaction with the STM tip. In the case of open shell atoms, this can be revealed in nonmonotonic behavior of the eigenchannel's transmissions as a function of the tip-adatom separation.