Abstract
The Kagome and related lattices have gained tremendous attention in the last few years. It is a model lattice for studying effects of frustration and a number of material synthesized, possess such a structure. The manifestation of exotic states such as Spin-Liquids and Valence Bond Crystals is currently debated.
In this talk I shall give a very brief overview of the background, and then present two recent studies: The first one is the investigation of the effect of doping on the quantum spin ½ system on the Kagome lattice. Here the t-J model is used and numerically investigated with the help of variational Monte-Carlo. Spin-Liquid and Valence-Bond-Crystal states are the trial states. The result is compared with exact diagonalization.
The second one is the investigation of classical spins on the extended Heisenberg model (J1-J2-model). The interesting physics happens at very low temperature, were different classical spin orders appear. To sample this region efficiently we resort to parallel tempering.