Dresden 2020 – wissenschaftliches Programm
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TT 33.5: Vortrag
Mittwoch, 18. März 2020, 10:30–10:45, HSZ 201
Bandwidth renormalization due to the intersite Coulomb interaction — Yann in 't Veld1, •Malte Schüler2,3, Tim Wehling2,3, Mikhail Katsnelson1, and Erik van Loon2,3 — 1Institute for Molecules and Materials, Radboud University — 2Bremen Center for Computational Materials Science, University Bremen — 3Institute for Theoretical Physics, University Bremen
The theory of correlated electrons is currently moving beyond the paradigmatic Hubbard U, towards the investigation of intersite Coulomb interactions. Recent investigations have revealed that these interactions are relevant for the quantitative description of realistic materials. Physically, intersite interactions are responsible for two rather different effects: screening and bandwidth renormalization. We use a variational principle to disentangle the roles of these two processes and study how appropriate the recently proposed Fock treatment of intersite interactions is in correlated systems. The magnitude of this effect in graphene is calculated based on cRPA values of the intersite interaction. We also apply the variational principle to benzene and find effective parameters comparable to those obtained by ab-initio density matrix downfolding.