Efficient ab-initio method for the calculation of frequency dependent non-linear optical response in semiconductors: application to second harmonic generation

TL;DR

This paper presents an efficient first-principles method for calculating the frequency-dependent second-harmonic generation in semiconductors, applying it to various materials and comparing correction techniques for improved accuracy.

Contribution

It introduces a LMTO implementation of the length-gauge formalism for second-harmonic generation, demonstrating the superiority of Hamiltonian correction over scissor's operator correction.

Findings

Hamiltonian correction method outperforms scissor's operator correction

Decomposition of responses reveals intra- and inter-band contributions

Application to multiple semiconductors validates the method's effectiveness

Abstract

A LMTO implementation of Aversa and Sipe's length-gauge formalism for calculating the full frequency dependent second-harmonic generation in the independent particle approximation is presented. It is applied to GaAs, GaP, 3C-SiC, c-BN and wurtzite and zincblende GaN and AlN. The use of the scissor's operator for correcting LDA errors is discussed and compared to an alternative approach in which the Hamiltonian is corrected. The latter is found to be superior. Decomposition in omega and 2 omega resonances and in intra- and inter-band contributions and in specific band-to-band contributions are presented.