Regensburg 2010 – scientific programme
Parts | Days | Selection | Search | Downloads | Help
TT: Fachverband Tiefe Temperaturen
TT 12: CE: Metal-Insulator Transition 1
TT 12.11: Talk
Tuesday, March 23, 2010, 12:15–12:30, H19
Quantum magnetism of the Hubbard model on the Triangular Lattice — •Hong-Yu Yang1, Andreas Läuchli2, Frederic Mila3, and Kai Phillip Schmidt1 — 1Lehrstuhl für Theoretische Physik I, Otto-Hahn-Strasse 4, TU Dortmund, 44221 Dortmund, Germany — 2Max Planck Institut für Physik komplexer Systeme, Nöthnitzerstrasse 38, 01187 Dresden, Germany — 3Institute for Theoretical Physics, EPF Lausanne, 1015 Lausanne, Switzerland
The organic compound κ-(BEDT-TTF)2Cu2(CN)3 exhibits strong evidence for a spin liquid phase at low temperatures. To study this possible spin liquid phase we investigate the quantum magnetism of the Hubbard model on the isotropic and anisotropic triangular lattice at half filling. First, we quantitatively derive effective quantum spin models using perturbative continuous unitary transformations. The accuracy of this spin model is determined by comparing it with exact diagonalizations (ED) on the original Hubbard model. In the second step we use ED to analyze the properties of the spin model on larger clusters. We find clear evidence for the existence of a spin liquid phase located between the long-range ordered antiferromagnet and the metallic phase. Finally, the anisotropic case is tackled which is expected to give further insights into the quantum magnetism of the organic compound.