Optical properties of real surfaces: Local-field effects at oxidized Si(100)(2x2) computed with an efficient numerical scheme
|Title||Optical properties of real surfaces: Local-field effects at oxidized Si(100)(2x2) computed with an efficient numerical scheme|
|Publication Type||Palaiseau Article|
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|Author Address|| |
Caramella, L (Reprint Author), Univ Milan, ETSF, Via Celoria 16, I-20133 Milan, Italy. Univ Milan, ETSF, I-20133 Milan, Italy. Univ Milan, Dipartimento Fis, I-20133 Milan, Italy. CNISM, I-20133 Milan, Italy. Univ Paris 06, ETSF, F-75015 Paris, France. Univ Paris 06, INSP, F-75015 Paris, France. Univ Paris 07, F-75015 Paris, France. CNRS, UMR 7588, F-75015 Paris, France. Ecole Polytech, ETSF, F-91128 Palaiseau, France. Ecole Polytech, Solides Irradies Lab, CNRS UMR 7462, CEA, F-91128 Palaiseau, France.
|Caramella, L, Onida, G, Finocchi, F, Reining, L, Sottile, F|
|Publisher||AMERICAN PHYSICAL SOC|
|Year of Publication||2007|
|Journal||Phys. Rev. B|
|Type of Work||Article|
We show the application of an efficient numerical scheme to obtain the independent-particle dynamic polarizability matrix chi((0))(r,r('),omega), a key quantity in modern ab initio excited-state calculations. The method has been applied to the study of the optical response of a realistic oxidized silicon surface, including the effects of crystal local fields. The latter are shown to substantially increase the surface optical anisotropy in the energy range below the bulk band gap. Our implementation in a large-scale ab initio computational code allows us to make a quantitative study of the CPU time scaling with respect to the system size, and demonstrates the real potential of the method for the study of excited states in large systems.