Year: 2014
Type: article
Abstract: In the framework of dielectric theory, the static non-local self-energy of an electron near an ultra-thin polarizable layer has been calculated and applied to study binding energies of image-potential states near free-standing graphene. The corresponding series of eigenvalues and eigenfunctions have been obtained by numerically solving the one-dimensional Schrödinger equation. The image-potential state wave functions accumulate most of their probability outside the slab. We find that the random phase approximation (RPA) for the non-local dielectric function yields a superior description for the potential inside the slab, but a simple Fermi–Thomas theory can be used to get a reasonable quasi-analytical approximation to the full RPA result that can be computed very economically. Binding energies of the image-potential states follow a pattern close to the Rydberg series for a perfect metal with the addition of intermediate states due to the added symmetry of the potential. The formalism only requires a minimal set of free parameters: the slab width and the electronic density. The theoretical calculations are compared with experimental results for the work function and image-potential states obtained by two-photon photoemission.
Source: New Journal of Physics
Authors: P L de Andres, P M Echenique, D Niesner, Th Fauster, A Rivacoba
Language: English
Subfield: Materials Chemistry
Field: Materials Science
Domain: Physical Sciences
Open Access status: gold
Estimated APC paid: $2,610
OpenAlex ID: W2156065014