题 目：Deconfined spinons at the Neel-VBS transition

报告人：Anders Sandvik 教授 （美国Boston University）

时 间：6月20日（周一）下午3：00-5:00

地 点：科技楼M2会议室

报告摘要：Adding certain multi-spin interactions of strength Q to the standard 2D Heisenberg antiferromagnet with exchange J (the J-Q model) leads to the destruction of Neel order and a transition into a dimerized valence-bond-solid (VBS) state.Quantum Monte Carlo (QMC) simulations of this system reveal scaling behavior at the Neel-VBS transition consistent with a continuous quantum critical point, in agreement with the theory of "deconfined" quantum criticality. There are, however, significant scaling corrections,possibly logarithmic, that had not been anticipated. These corrections may actually be a fingerprint of deconfined spinons. I will discuss the latest QMC evidence for a continuous ground state transition as well as signatures of spinon deconfinement in thermodynamic properties. I will also discuss how one can directly"see" spinons in quantum Monte Carlo simulations.


简历：Anders Sandvik教授是美国波士顿大学教授，美国物理学会会士（APSFellow，不超过0.5%），在计算物理和量子磁性方面享有很高的声望。他所发明的SSE量子蒙特卡洛方法和投影算子蒙特卡洛方法在国际上有重要影响，已被广泛使用。他在2002年关于SSE的文章获得Physical Review E当年最高引用率。Sandvik教授迄今已发表各类论文一百多篇，其中Physical ReviewLetters三十篇。