Onedimensional potential for imagepotential states on graphene
Abstract
In the framework of dielectric theory, the static nonlocal selfenergy of an electron near an ultrathin polarizable layer has been calculated and applied to study binding energies of imagepotential states near freestanding graphene. The corresponding series of eigenvalues and eigenfunctions have been obtained by numerically solving the onedimensional Schrödinger equation. The imagepotential state wave functions accumulate most of their probability outside the slab. We find that the random phase approximation (RPA) for the nonlocal dielectric function yields a superior description for the potential inside the slab, but a simple FermiThomas theory can be used to get a reasonable quasianalytical approximation to the full RPA result that can be computed very economically. Binding energies of the imagepotential 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 imagepotential states obtained by twophoton photoemission.
 Publication:

New Journal of Physics
 Pub Date:
 February 2014
 DOI:
 10.1088/13672630/16/2/023012
 arXiv:
 arXiv:1403.0391
 Bibcode:
 2014NJPh...16b3012D
 Keywords:

 Condensed Matter  Materials Science;
 Condensed Matter  Mesoscale and Nanoscale Physics
 EPrint:
 24 pages