Ab initio calculation of many-body effects on the second-harmonic generation spectra of hexagonal SiC polytypes

作者：Huebener Hannes; Luppi Eleonora; Veniard Valerie

来源：Physical Review B, 2011, 83(11): 115205.

DOI：10.1103/PhysRevB.83.115205

We investigate the influence of crystal local fields and excitonic effects on the spectrum of the second harmonic generation of three polytypes of silicon carbide by using time-dependent density-functional theory including many-body effects, namely, quasiparticle corrections through the scissors operator, crystal local field effects, and excitonic interaction. The relation between the scalar density response and the components of the rank 3 tensor d((2)) is established by calculating the response along different polarization directions. We find that local-field effects, although necessary for a rigorous description in the theory, yield only small contributions to the spectra, whereas excitonic effects have a strong influence on the second harmonic generation. We compare static values of the second harmonic coefficients to recent measurements and obtain very good agreement.

• 出版日期2011-3-22