Anisotropic optical response of the diamond (111)-2x1 surface

TL;DR

This study investigates the anisotropic optical properties of the reconstructed diamond (111) surface using a tight-binding approach, revealing significant dielectric anisotropy linked to surface reconstruction and comparing well with experimental data.

Contribution

It provides a detailed microscopic analysis of the surface's optical anisotropy and electronic transitions, enhancing understanding of the diamond (111) surface's optical behavior.

Findings

Large dielectric anisotropy due to surface reconstruction

Agreement with experimental reflectance and loss spectra

Proposes further experiments to clarify surface electronic structure

Abstract

The optical properties of the 2$\times$1 reconstruction of the diamond (111) surface are investigated. The electronic structure and optical properties of the surface are studied using a microscopic tight-binding approach. We calculate the dielectric response describing the surface region and investigate the origin of the electronic transitions involving surface and bulk states. A large anisotropy in the surface dielectric response appears as a consequence of the asymmetric reconstruction on the surface plane, which gives rise to the zigzag Pandey chains. The results are presented in terms of the reflectance anisotropy and electron energy loss spectra. While our results are in good agreement with available experimental data, additional experiments are proposed in order to unambiguously determine the surface electronic structure of this interesting surface.