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.
Evaluation of conduction eigenchannels of an adatom probed by an STM tip
M. Polok, D. V. Fedorov, A. Bagrets, P. Zahn, and I. Mertig
Phys. Rev. B 83, 245426