Resolubility of Image-Potential Resonances

TL;DR

This paper develops a comprehensive theory for image-potential states that are resonant with bulk states, predicting multiple well-resolved resonances on metal surfaces across various coupling strengths.

Contribution

It extends the multiple scattering approach to strong coupling regimes, allowing for the prediction of image-potential resonances without specific potential forms.

Findings

Resonances exist for arbitrary coupling strengths.

Multiple well-resolved resonances are predicted.

Resonances are expected on almost any metal surface.

Abstract

A theory of image-potential states is presented for the general case where these surface electronic states are resonant with a bulk continuum. The theory extends the multiple scattering approach of Echenique and Pendry into the strong coupling regime while retaining independence from specific forms of surface and bulk potentials. The theory predicts the existence of a well-resolved series of resonances for arbitrary coupling strengths. Surprisingly, distinct image-potential resonances are thus expected to exist on almost any metal surface, even in the limiting case of jellium.