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PIRSA:12050039

Spin liquid and Deconfined Criticality in a Kagome Lattice Bose-Hubbard Model

APA

Melko, R. (2012). Spin liquid and Deconfined Criticality in a Kagome Lattice Bose-Hubbard Model. Perimeter Institute for Theoretical Physics. https://pirsa.org/12050039

Roger Melko University of Waterloo

Talk numberPIRSA:12050039
Talk Type Conference

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.