Spin liquid and Deconfined Criticality in a Kagome Lattice BoseHubbard Model Speaker(s): Roger Melko
Abstract: We present largescale quantum Monte Carlo simulations on a signproblem free BoseHubbard model on the kagome lattice. This model supports a quantum Z2 spin liquid phase with fractional excitations and topological order, which can be characterized definitively through calculation of the topological entanglement entropy. I will outline how the entanglement entropy can be measured in general using a direct implementation of the "replica trick", which allows for the study of entanglement scaling in a variety of other models amenable to study by QMC. Finally, I will examine the kagome model's superfluid/spinliquid transition, which is an example of an exotic deconfined quantum critical point called XY*, mediated by the fractional charges. This fact is demonstrated in several universal quantities that we measure, and may also be reflected the scaling of entanglement entropy at the critical point.
Date: 03/05/2012  3:00 pm
