Tigran A. Sedrakyan
The William I. Fine Theoretical Physics Institute, University of Minnesota, USA
Date: 6月27日（周五）下午2:00
Location: 唐仲英楼B501
The recently discovered boson systems on frustrated optical lattices are remarkable for their capacity to explore physics that may not be revealed in any other way. Examples include moat lattices with the lowest Bloch band having a degenerate minimum along a closed contour in the reciprocal space -- the Moat. It is entirely the effect of correlations which lifts this degeneracy and leads to an amazing variety of completely new quantum many-body states. In this talk I will argue that the frustration in XY model, or alternatively a model of hard-core bosons, on graphene's honeycomb lattice stabilizes a variety of novel spin liquid phases including composite fermion state and chiral spin liquid. These are topologically nontrivial ground states leading to the exponential decay of order parameter correlation fluctuations in the bulk and to the power-law behavior along the edges.