Elastic electron scattering in quantum corrals: The importance of the shape of the adatom potential

TL;DR

This paper develops a realistic scattering-matrix approach to model surface electron waves in quantum corrals, showing that the shape of adatom potentials is crucial for accurately reproducing experimental results without invoking bulk scattering channels.

Contribution

The authors introduce a scattering-matrix technique that incorporates smooth potential profiles of adatoms, improving the agreement with experiments over previous point-scatterer models.

Findings

Quantitative agreement with experimental observations

Surface states are decoupled from bulk electrons

Realistic potential profiles are essential for modeling

Abstract

We report elastic scattering theory for surface electron waves in quantum corrals defined by adatoms on the surface of noble metals. We develop a scattering-matrix technique that allows us to account for a realistic smooth potential profile of the scattering centers. Our calculations reproduce quantitatively all the experimental observations, which is in contrast to previous theories (treating the adatoms as point scatterers) that require additional inelastic channels of scattering into the bulk in order to achieve the agreement with the experiment. Our findings thus indicate that surface states are not coupled to the bulk electrons.