Regensburg 2022 – wissenschaftliches Programm

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TT: Fachverband Tiefe Temperaturen

TT 16: Correlated Electrons: Method Development

TT 16.10: Vortrag

Mittwoch, 7. September 2022, 12:15–12:30, H10

Single-boson-exchange-fRG application to the two-dimensional Hubbard model at weak coupling — •Sarah Heinzelmann¹, Kilian Fraboulet¹, Pietro Bonetti², Aiman Al-Eryani¹, Demetrio Vilardi², Alessandro Toschi³, and Sabine Andergassen¹ — ¹Eberhard Karls Universität Tübingen — ²Max Planck Institut Stuttgart — ³Technische Universität Wien

We illustrate the computational advantages of the recently introduced single-boson exchange (SBE) formulation for the one-loop functional renormalization group (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.