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TT: Fachverband Tiefe Temperaturen
TT 94: Correlated Electrons: Other Theoretical Topics
TT 94.2: Talk
Thursday, March 15, 2018, 15:15–15:30, H 3010
Lattice coordination vs. space dimension in 2nd order phase transitions: a dynamical vertex approximation study — •Andreas Hausoel1, Georg Rohringer2, Thomas Schäfer3, Giorgio Sangiovanni1, and Alessandro Toschi4 — 1University of Wuerzburg, Germany — 2Russian Quantum Center, Moscow, Russia — 3École Polytechnique and Collège de France, Paris, France — 4Technical University of Vienna, Austria
The dynamical vertex approximation (DΓA) includes spatial correlations of all length scales beyond the dynamical mean-field theory (DMFT) description. The most relevant changes due to nonlocal fluctuations are a deviation from the mean-field critical behaviour and a sizeable reduction of magnetic ordering temperatures [1].
Here we extend the analysis to different lattice types; in particular, we compare DΓA calculations for the simple, the body-centered and face-centered cubic lattices to the corresponding DMFT ones.
On general grounds, one expects a overall reduction of the differences w.r.t. DMFT, the larger the coordination number of the lattice considered is.
Our analysis will clarify the underlying aspects of this trend, investigating the difference between (i) an increase of the coordination number by changing the lattice type (i.e. keeping space dimension fixed), and (ii) an increase of coordination number by keeping the lattice type fixed and increasing the space dimension.
G. Rohringer, A. Toschi, A. Katanin, K. Held, PRL 107, 256402.