SKM 2021 – wissenschaftliches Programm

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TT: Fachverband Tiefe Temperaturen

TT 9: Poster Session: Correlated Electrons

TT 9.28: Poster

Dienstag, 28. September 2021, 13:30–16:00, P

Real-space cluster dynamical mean-field theory: Center focused extrapolation on the one- and two particle level — Marcel Klett¹, •Nils Wentzell², Thomas Schaefer¹, Fedor Simkovic³, Olivier Parcollet², Sabine Andergassen⁴, and Philipp Hansmann⁵ — ¹Theory of strongly correlated quantum matter, Max Planck Institute for Solid State Research, Stuttgart — ²Center for Computational Quantum Physics, Flatiron institute, NYC — ³College de France, Paris — ⁴Institut fuer Theoretische Physik and Center for Quantum Science, University Tuebingen — ⁵Institut für Theoretische Physik, Friedrich-Alexander-University Erlangen-Nuernberg

We revisit the cellular dynamical mean-field theory (CDMFT) for the single band Hubbard model on the square lattice at half filling, reaching real-space cluster sizes of up to 9 x 9 sites. Using benchmarks against direct lattice diagrammatic Monte Carlo at high temperature, we show that the self-energy obtained from a cluster center focused extrapolation converges faster with the cluster size than the periodization schemes previously introduced in the literature. The same benchmark also shows that the cluster spin susceptibility can be extrapolated to the exact result at large cluster size, even though its spatial extension is larger than the cluster size.

We acknowledge financial support from the Deutsche Forschungsgemeinschaft (DFG) through ZUK 63 and Project No. AN 815/6-1