PPGF/CCET

TITLE: Constructing realistic low-energy effective models of materials

Palestrante: Prof. Dr. João Nuno Barbosa Rodrigues (Universidade Federal do ABC)

ABSTRACT: Recent advances in algorithms and computer performance enabled us to accurately simulate the many-body problem of systems with a few hundred electrons. Still, this is often too small to allow for realistic studies of low-energy properties of materials which generally take place at much larger length scales. Condensed Matter physicists thus frequently resort to working with simple effective models, justified by clever physical arguments and experimental observations. Such models often provide valuable physical insight and enable larger length-scale studies. However, since model parameters are invariably unknown, this approach often lacks predictive power, an issue that turns more significant in materials with strong electronic correlations. Being able to controllably construct accurate effective models of materials would allow us to bypass this conundrum. In this colloquium I will present a methodology that attempts to fill this gap by using highly accurate many-body simulations of a material to inform the construction of effective model Hamltonians that approximate the material's low-energy physics. I will show some results on low-dimensional materials and discuss prospects for this technique.                                                

Data: 02/05/2024         Horário: 16:30 h         Link: meet.google.com/eta-bzco-bup