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TT: Fachverband Tiefe Temperaturen
TT 7: Correlated Electrons: Spin Systems, Itinerant Magnets 1
TT 7.2: Talk
Monday, March 11, 2013, 09:45–10:00, H19
Emergent critical phase and Ricci flow in a 2D frustrated Heisenberg model — •Peter Orth1, Premala Chandra2, Piers Coleman2, and Jörg Schmalian1 — 1Institute for Theoretical Condensed Matter Physics, Karlsruhe Institute of Technology (KIT), 76128 Karlsruhe, Germany — 2Center for Materials Theory, Department of Physics and Astronomy, Rutgers University, Piscataway, New Jersey 08854, USA
We introduce a two-dimensional frustrated Heisenberg antiferromagnet on interpenetrating honeycomb and triangular lattices [1]. Classically the two sublattices decouple, and "order from disorder" drives them into a coplanar state. Applying Friedan’s geometric approach to nonlinear sigma models, we obtain the scaling of the spin-stiffnesses governed by the Ricci flow of a 4D metric tensor. At low temperatures, the relative phase between the spins on the two sublattices is described by a six-state clock model with an emergent critical phase and two Berezinskii-Kosterlitz-Thouless (BKT) phase transitions.
[1] P. P. Orth, P. Chandra, P. Coleman, and J. Schmalian, arXiv:1206.5740v1 (2012) (accepted for Phys. Rev. Lett.)