Reflectance anisotropy spectra of CdTe$(001)$ surfaces

We calculate reflectance anisotropy (RA) spectra of a clean Cd-terminated CdTe$(001)$ surface which exhibits $c(2 \times 2)$ reconstruction, and clean Te-terminated CdTe surfaces with $(2 \times 1)$, $(1 \times 2)$ and $c(2 \times 2)$ surface reconstructions. Theoretical spectra are obtained from two aproaches: an $ab$ $initio$ pseudopotential calculation in the framework of the density functional theory and within the local density approximation (DFT-LDA), and a microscopic formulation based on a semi- empirical tight binding approach which includes spin-orbit (SO) interactions$^1$. We show how RA spectrum changes when SO coupling is taken into account and compare our theoretical results with experimental results$^2$. We find a good agreement between experimental and theoretical spectra. \newline [1] R. A. V\'azquez-Nava, B. S. Mendoza and N. Arzate, Phys. Stat. Sol. b {\bf 242} 3022 (2005); R. A. V\'azquez-Nava, B. S. Mendoza and C. Castillo Phys. Rev. B {\bf 70}, 165306 (2004) \newline [2] R. E. Balderas-Navarro, K. Hingerl, W. Hilber, D. Stifter, A. Bonanni and H. Sitter, J. Vac. Sci. Technol. B {\bf 18} 2224 (2000).