北京师范大学郭文安教授报告
发布时间:2015.09.30
来源: 本站
报告人:北京师范大学 郭文安 教授
报告题目:Emergent topological and fractional excitations in a two-dimensional valence-bond solid
时间:2015年9月30日星期三上午9点30分
地点:物理馆323室
报告摘要:The Valence-bond solid (VBS) is one of the non-trivial non-magnetic
ground state which plays an essential role in the study of the deconfined
quantum criticality violating the standard Landau-Ginzburg-Wilson framework.
Spinons are emergent fractional excitations, which bind together in the VBS
state, but deconfine at the critical point separating the VBS from the
antiferromagnetic Neel state. Topological excitations can also arise in the VBS
state, although topological order has mainly been discussed in the context of
exotic states without any long-range order such as quantum spin liquids. In
this talk, I will present our recent projector quantum Monte Carlo studies of
the emergent topological excitations and the mechanism of the
confinement/deconfinement of spinons (holons) in the $J-Q$ model on the
two-dimensional square lattice, which has valence-bond solid order in its ground
state. A brief introduction to the projector quantum Monte Carlo method for
quantum spin models will also be included.}
%\talkspeaker{Wenan Guo received
his M.Sc.\ from the Lanzhou University in 1993 and his PhD from the Beijing
Normal University in 1996. He did his postdoc research at the Delft university
of technology in 1997-1998. Since 2004 he has been a professor at Beijing
Normal University. His main research interests are in quantum and classical
many-body physics, where he uses numerical methods to study both quantum and
thermal phase transitions in various statistical models.