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

Drawing nanostructures with povray

  Sometime ago I discovered povray, a ray tracing program which generates stunning three-dimensional graphics. I used it to draw nanostructures and in particular nanotubes in different configurations, hereafter the plots and the corresponding scripts: From left to right: 1) illuminated nanotube, STM_tips.pov 2) gated nanotube, gated_tube.pov 3) nanotube and STM tip, light_tube.pov

Efficient Gate-tunable light-emitting device made of defective boron nitride nanotubes

I published my first “Nature”, even if the lower level one, a Nature Scientific Reports: Efficient Gate-tunable light-emitting device made of defective boron nitride nanotubes: from ultraviolet to the visible Claudio Attaccalite, Ludger Wirtz, Andrea Marini & Angel Rubio Scientific Reports 3, Article number:2698 Boron nitride is a promising material for nanotechnology applications due to… 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

Optical excitations in a paradigmatic model dipeptide

We just post on arxiv a new paper on the optical excitations in a paradigmatic model dipeptide, here in the figure. We studied local and charge transfer excitations by means of state of the art GW and Bethe-Salpeter equations as implemented in the FIESTA code. In particular we focused on the effect of self-consistency in… Read More