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 collaborator Myrta Grüning gave a very interesting talk about the role of excitons in non-linear optical properties of 2D materials at the OSI 2017 conference. She discusses both second and third harmonic generation in low dimensional nanostructures. Slides of her talk are available here .
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.
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
Together with Myrta Gruning we just submitted a new paper on second harmonic generation(SHG) in two-dimensional materials, h-BN and MoS2. We calculated the SHG using a real-time approach that we recently developed. We included both local field effects and electron-hole interaction at the level of screened exchange , without any additional approximation. Our approch is… Read More
We present an ab-initio real-time based computational approach to nonlinear optical properties in Condensed Matter systems. The equation of motions, and in particular the coupling of the electrons with the external electric field, are derived from the Berry phase formulation of the dynamical polarization. The zero-field Hamiltonian includes crystal local field effects and the renormalization… Read More