Berlin 2015 – wissenschaftliches Programm

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TT: Fachverband Tiefe Temperaturen

TT 5: Correlated Electrons: Spin Systems and Itinerant Magnets – Frustrated Magnets 1 (jointly with MA)

TT 5.4: Vortrag

Montag, 16. März 2015, 10:15–10:30, H 0110

Spin dynamics of the bilinear-biquadratic spin-one Heisenberg model on the triangular lattice — Annika Völl and •Stefan Wessel — Institut für Theoretische Festkörperphysik, RWTH Aachen University, Germany

We study thermodynamic properties as well as the dynamical spin and quadrupolar structure factors of the O(3)-symmetric spin-1 Heisenberg model with bilinear-biquadratic exchange interactions on the triangular lattice. Based on a sign-problem-free quantum Monte Carlo approach, we access both the ferromagnetic and the ferroquadrupolar ordered, spin nematic phase as well as the SU(3)-symmetric point which separates these phases. Signatures of Goldstone soft-modes in the dynamical spin and the quadrupolar structure factors are identified, and the properties of the low-energy excitations are compared to the thermodynamic behavior observed at finite temperatures as well as to Schwinger-boson flavor-wave theory.