Ab init io Many Body Perturbation Theory in Condensed Matter: From “conventional” numerical approaches to Machine Learning

Venue: Polo Ferrari 1 via Sommarive 5 Povo - Room A107
Time: 14.30

dr. Paolo E. Trevisanutto
European Center for Theoretical Studies in Nuclear Physics and Related Areas (ECT*-FBK)
Trento Institute for Fundamental Physics and Applications (TIFPA-INFN)
Fondazione Bruno Kessler (FBK)

ABSTRACT
The exciton, electron-hole (e-h) quasi-particle has an important role in both fundamental and applied physics, especially for 2D materials where the binding energy is high. This peculiar effect determines the stable and localized excitons that can be exploited either for qubits or, by using the self-trapping effects, for Single Light Emitter devices.
In this talk, we review the current state of the art from the ab initio many-body perturbation theory (MBPT), the GW-Bethe-Salpeter Equation (GW-BSE) in the linear regime. In addition, we report new theoretical works on the nonlinear optical response by using the Time-dependent Bethe-Salpeter Equation(TD-BSE)) and Time-Dependent Density Functional Theory (TD-DFT).
In parallel, we present a Statistical Mechanics (SM) model of deep neural networks, connecting the energy-based and the feed forward
networks (FFN) approach. We infer that FFN can be understood as performing three basic steps: encoding, representation validation and propagation.
Finally, we will discuss the possibility of inserting deep neural network approaches to improve and expedite the ab initio MBPT calculations in the Condensed Matter Physics.

Scientific Coordinator:
dr. Iacopo Carusotto