Berlin 2012 – wissenschaftliches Programm

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TT: Fachverband Tiefe Temperaturen

TT 19: Correlated Electrons: (General) Theory 2

TT 19.7: Vortrag

Dienstag, 27. März 2012, 11:00–11:15, H 3010

Phase transitions of the three-state (anti-)ferromagnetic Potts model in transverse field — •Marc Daniel Schulz^1,4, Sébastien Dusuel², Roman Orùs³, Julien Vidal⁴, and Kai Phillip Schmidt¹ — ¹Lehrstuhl für Theoretische Physik I, Technische Universität Dortmund, Otto-Hahn-Straße 4, 44221 Dortmund, Germany — ²Lycée Saint-Louis, 44 Boulevard Saint-Michel, 75006 Paris, France — ³Max-Planck-Institut für Quantenoptik, Hans-Kopfermann-Straße 1, 85748 Garching, Germany — ⁴Laboratoire de Physique Théorique de la Matière Condensée, CNRS UMR 7600, Université Pierre et Marie Curie, 4 Place Jussieu, 75252 Paris Cedex 05, France

The investigation of phase transitions in two-dimensional quantum lattice systems is a challenging task. Here, we study the three-state Potts model on a two-dimensional square lattice in transverse field for antiferromagnetic and ferromagnetic coupling. To this end, we combine the methods of perturbative continuous unitary transformations (pCUT) and variational techniques using infinite projected entangled pair states(iPEPS). For the ferromagnetic coupling, we confirm the already known first-order nature of the phase transition, whereas for the anti-ferromagnetic coupling we provide strong evidence for a novel second-order phase transition compatible with the 3dXY universality class.