Category Archives: second harmonic generation

How strong is the Second Harmonic Generation in single-layer monochalcogenides?

Single-layer monochalcogenides have recently attracted much attention in the scientific community for their strong non-linear response, in particular the second harmonic generation(SHG). The origin of this strong response is still debated. A strong mismatch exist between theory and experiments. In order to clarify this issue, in this work we performed first-principles calculation of linear and… Read More

My thesis for the Habilitation à Diriger des Recherches

The first draft of my  thesis for the accreditation to direct research (Habilitation à Diriger des Recherches) is available online. The thesis covers my studies of the non-linear response in solids and nanostructures by means of real-time simulations.  In the thesis I discuss how to couple electrons and external fields by means of Modern Theory… Read More

Density Functional Polarization Theory

We present a new paper on Density Functional Polarization Theory (DFPT). This theory is an extension of Time-Dependent-DFT where the exchange correlation functional depends not only from the density but also from the polarization P. Thanks to this explicit dependence on P it is possible  solve different problems of TD-DFT in periodic systems with a… Read More

Nonlinear response of solids within the GW plus Bethe-Salpeter approximation

My new talk for the GDR-Corr is available online. In this talk I will present our new (probably not so new now) approach to calculate non-linear response in extended systems within the GW plus Bethe-Salpeter equation. I  put different references in the presentation that can be interesting for the reader.

Strong second harmonic generation in SiC, ZnO, GaN two-dimensional hexagonal crystals from first-principles many-body calculations

We published a new paper on the second harmonic generation(SHG) in two-dimensional hexagonal crystals SiC, ZnO and GaN. The SHG is calculated within the so called GW plus Bethe-Salpter formalism, using a real-time implementation proposed by some of us. We found that these system present a large region with a strong SHG before the absorption… Read More