Tag Archives: second harmonic generation

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

Excitons in second harmonic generation

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

Nonlinear optics by means of the dynamical Berry-phase

We present an ab-initio real-time based computational approach to nonlinear optical properties in Condensed Matter systems[1]. 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.[2] The zero-field Hamiltonian includes crystal local field effects and the renormalization… Read More