Ab initiostudy of the nonlinear optics of III-V semiconductors in the terahertz regime

Eric Roman, Jonathan R. Yates, Marek Veithen, David Vanderbilt, Ivo Souza
2006 Physical Review B  
We compute from first principles the infrared dispersion of the nonlinear susceptibility χ^(2) in zincblende semiconductors. At terahertz frequencies the nonlinear susceptibility depends not only on the purely electronic response χ^(2)_∞, but also on three other parameters C_1, C_2 and C_3 describing the contributions from ionic motion. They relate to the TO Raman polarizability, the second-order displacement-induced dielectric polarization, and the third-order lattice potential. Contrary to
more » ... vious theory, we find that mechanical anharmonicity (C_3) dominates over electrical anharmonicity (C_2), which is consistent with recent experiments on GaAs. We predict that the sharp minimum in the intensity of second-harmonic generation recently observed for GaAs between ω_ TO/2 and ω_ TO does not occur for several other III-V compounds.
doi:10.1103/physrevb.74.245204 fatcat:xnngquy2gvcbddctf2onweorkm