Category Archives: research

Optical properties of Cu-chalcogenide photovoltaic absorbers from self-consistent GW and the Bethe-Salpeter equation

We pubblised a new paper1 on the optical properties of Cu-chalcogenide photovoltaic absorbers. In this manuscript we  calculate the optical response of the less studied, but promising, Cu2ZnGe(S,Se)4 compounds, opening the way to predictive calculations of still unknown materials by means of self-consistent GW plus Bethe-Salpeter equations. Moreover in this paper we solved the problem… Read More

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

Exploring approximations to the GW self-energy ionic gradients

A new paper is out on the different approximation in  GW  for the electron-phonon couping matrix elements. In particular we tested two approximation the static screening (COHSEX) and the constant screening respect to the phonon displacement. We found that the first approximation miserably fails to reproduce the G0W0 results while the second introduce a negligible… Read More

Graphene research is slowly fading away

After the discover of graphene in 2014 by Geim and Novoselov that got the Nobel price in 2010, scientists have worked hard to investigate all possible properties and possible uses of this material. At the beginning graphene was proposed as possible candidate to substitute silicon in electronics, due its extreme high conductivity. However differently from… Read More

CNRS cuts research positions by more than one-fourth in the last 5 years

CNRS (National Scientific Research Center) is the largest research center in France. It employes about 11.000 researchers and its domain of activity ranges from physics to sociology, from chemistry to electronics and so on. Every year researchers are recruited by means of a national open competitive exam. The selection is composed of two parts a… Read More

GW renormalization of the electron-phonon coupling

My new presentation on the “GW renormalization of the electron-phonon coupling” is available online. This is the talk I gave to the “Correlation Meeting 2014” organized by Pina Romaniello. In this presentation I show that GW corrections are important not only for band structure and energy levels but they also renormalise the electron-phonon matrix elements…. Read More