Berlin 2018 – wissenschaftliches Programm
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TT: Fachverband Tiefe Temperaturen
TT 91: Correlated Electrons: Method Development
TT 91.6: Vortrag
Donnerstag, 15. März 2018, 16:15–16:30, H 0104
Efficient Bethe-Salpeter equations’ inversion in dynamical mean-field theory — •Agnese Tagliavini1,3, Stefan Hummel2, Nils Wentzell5, Sabine Andergassen3, Alessandro Toschi4, and Georg Rohringer1 — 1Institute for Solid State Physics, Vienna University of Technology, 1040 Vienna, Austria — 2Physics of Nanostructured Materials, Faculty of Physics, University of Vienna, 1090 Vienna, Austria — 3Institut für Theoretische Physik and Center for Quantum Science, Universität Tübingen, Auf der Morgenstelle 14, 72076 Tübingen, Germany — 4Russian Quantum Center, 143025 Skolkovo, Russia — 5Institut de Physique Théorique (IPhT), CEA, CNRS, 91191 Gif-sur-Yvette, France
Quantum many-body calculations of two-particle Greens’ and vertex functions represent a very important, but also highly demanding task. Hence, a particular effort has been recently devoted to develop novel algorithmic procedures aimed at saving both memory and computational time. In this talk, we present two efficient and numerically stable asymptotic-based algorithms designed to correctly determine the local two-particle irreducible vertex in all scattering channels by means of the inversion of the corresponding Bethe-Salpeter equations. The latter operation is, in fact, a fundamental step in diagrammatic extensions of DMFT like the Dynamical Vertex Approximation (DΓA). The two algorithms have been tested, and critically compared, for the single-band 3D Hubbard model in the vicinity of the Mott transition, where the asymptotic structures of the vertex functions become dominant.