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MM: Fachverband Metall- und Materialphysik
MM 54: Focus Session: Frontiers of Electronic-Structure Theory: Correlated Electron Materials VI (joint session O/MM/DS/TT/CPP)
MM 54.5: Talk
Thursday, March 15, 2018, 11:30–11:45, HL 001
Ab-initio treatment of non-local electronic correlations with the dynamical vertex approximation — •Anna Galler1, Patrik Thunström2, Patrik Gunacker3, Josef Kaufmann3, Matthias Pickem3, Jan M. Tomczak3, and Karsten Held3 — 1Centre de Physique Theorique, Ecole Polytechnique, 91128 Palaiseau, France — 2Department of Physics and Astronomy, Materials Theory, Uppsala University, 75120 Uppsala, Sweden — 3Institute of Solid State Physics, TU Wien, 1040 Vienna, Austria
Recently, approaches such as the dynamical vertex approximation (DΓA) or dual-fermion method have been developed. These diagrammatic approaches are going beyond dynamical mean-field theory (DMFT) by including non-local electronic correlations on all length scales as well as the local DMFT correlations. Here we present our efforts to extend the DΓA methodology to ab-initio materials calculations (AbinitioDΓA). Our approach is a unifying framework which includes both, GW and DMFT-type of diagrams, but also important non-local correlations beyond, e.g. non-local spin fluctuations. In our multi-band implementation we are using a worm sampling technique within continuous-time quantum Monte Carlo in the hybridization expansion to obtain the DMFT vertex, from which we construct the reducible vertex function in a ladder approximation. As a first application we show results for transition metal oxides. Support by the ERC project AbinitioDGA (306447) is acknowledged.
References: [1] A. Galler, P. Thunström, P. Gunacker, Jan M. Tomczak, and K. Held, Physical Review B 95, 115107 (2017)