PIRSA:12050039  ( MP4 Medium Res , MP4 Low Res , MP3 , PDF ) Which Format?
Spin liquid and Deconfined Criticality in a Kagome Lattice Bose-Hubbard Model
Speaker(s): Roger Melko
Abstract: We present large-scale quantum Monte Carlo simulations on a sign-problem free Bose-Hubbard 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/spin-liquid 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
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