Abstract

We present ab initio calculations to investigate second harmonic generation (SHG) response of single wall zigzag pristine boron nitride nanotubes (BNNTs) and BNNTs modified by the molecular hydrogen adsorption. Calculations have been performed using density functional theory (DFT) within the local-density approximation (LDA) together with the GW Green function method to determine the band gap. A length gauge approach has been used to calculate the nonlinear optical response with the scissors correction to obtain the nonlinear susceptibility of the zigzag BNNTs. We have found that, contrary to reports in the literature, the (5,0) and (9,0) BNNTs have a non vanishing SHG response. We have also found that SHG intensity decreases with the increase of the molecular hydrogen coverage.

© 2014 Optical Society of America