Regensburg 2022 – wissenschaftliches Programm
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TT: Fachverband Tiefe Temperaturen
TT 21: Correlated Electrons: Poster Session
TT 21.30: Poster
Mittwoch, 7. September 2022, 15:00–18:00, P1
Single-boson exchange fRG application to the two-dimensional Hubbard model at weak coupling — Kilian Fraboulet1, •Sarah Heinzelmann1, Pietro Bonetti2, Aiman Al-Eryani1, Demetrio Vilardi2, Alessandro Toschi3, and Sabine Andergassen1 — 1Institut für Theoretische Physik and Center for Quantum Science, Universität Tübingen, Auf der Morgenstelle 14, 72076 Tübingen, Germany — 2Max Planck Institute for Solid State Research, Heisenbergstrasse 1, D-70569 Stuttgart, Germany — 3Institute of Solid State Physics, Vienna University of Technology, 1040 Vienna, Austria
The functional renormalization group (fRG) is one of the most modern implementation of the renormalization group and has proven successful in the description of various many-body quantum systems, in condensed matter theory and beyond (quantum chromodynamics, nuclear physics, ...). We illustrate in this work the computational advantages of the recently introduced single-boson exchange (SBE) formulation for the one-loop fRG applied to the two-dimensional Hubbard model.
We present a detailed analysis of the physical susceptibilities and their evolution with temperature and interaction strength, both at half filling and finite doping. We find that the rest functions describing the corrections beyond the SBE contributions play a negligible role in the weak coupling regime. The SBE formulation of the fRG flow hence allows for a substantial reduction of the numerical effort in the treatment of the two-particle vertex function, paving a promising route for future multiboson and multiloop extensions.