Prof. ZHOU, Yi (周毅)

Department of Physics, Zhejiang University

Abstract: In this talk, we introduce fermionic “triplons” to describe spin S=1 quantum antiferromagnets. Within this representation, we discuss the possibility of coexistence and competition between quantum spin liquids, Neel order and spin nematic order on 2D triangular lattices. Then we apply this theory to antiferromagnetic chains with spin quadratic-biquadratic exchanges and explain how the non-trivial topological structure distinguishes the Haldane phase from dimerized phase in mean field level. Finally, we demonstrate Gutzwiller projection through variational Monte Carlo will refine the mean field results and lead to amazing good agreement with exact solutions and DMRG in 1D.

报告人简介：周毅，浙江大学物理系特聘研究员。1998年7月本科毕业于清华大学物理系；2004年1月于清华大学高等研究院获得博士学位；之后在德国、香港等地做博士后研究和访问学者；于2009年7月加入浙江大学物理系。主要研究方向为量子多体问题和理论凝聚态物理。目前的研究兴趣在于在探索Mott绝缘体、非常规超导体、量子磁体等凝聚态系统中的新奇量子现象.

 Date&Time: January 10, 2012（Tuesday）14:30 – 15:30
 Location: 606 Conference Room