Regensburg 2016 – wissenschaftliches Programm
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TT: Fachverband Tiefe Temperaturen
TT 61: Correlated Electrons: (General) Theory 1
TT 61.1: Vortrag
Donnerstag, 10. März 2016, 09:30–09:45, H18
Collective magnetic excitations in correlated systems: self-consistent dual boson approach — Friedrich Krien1, Evgeny Stepanov2, Erik van Loon2, Andrey Katanin3, Mikhail Katsnelson2, Alexey Rubtsov4, and •Alexander Lichtenstein1 — 1University of Hamburg — 2Radboud University Nijmegen — 3Institute of Metal Physics, Ekaterinburg — 4Moscow State University
We propose an efficient dual boson scheme for correlated magnetic systems, which extends the local dynamical mean-field theory to non-local interactions and collective excitations. The theory is fully self-consistent both on the one and on the two-particle level, thus describing the formation of collective magnetic modes as well as the renormalization of electrons and magnons spectra on equal footing. The method employs exact solution of effective impurity model consists of both fermion and spin-boson hybridization functions. We show that the theory is naturally described by a dual Luttinger-Ward functional and obeys the relevant conservation laws for magnetic excitations. We compare numerical results for the Hubbard model with non-local magnetic interactions with extended DMFT solution.