报告题目：Disorder operator  and surface quantum criticality

报告人：王艳成 副教授 （北京航空航天大学杭州国际创新学院）

报告时间：2025年1月9日（周四） 15：00-16：00

报告地点：北洋园校区 32 教 252 室

报告摘要：

      The disorder operator is often designed to reveal the conformal field theory (CFT) information in quantum many-body systems. By using large-scale quantum Monte Carlo simulation, we study the scaling behavior of disorder operators on the surface in the two-dimensional Heisenberg model on the square-octagon lattice with gapless topological edge state. In the Affleck-Kennedy-Lieb-Tasaki phase, the disorder operator is shown to hold the perimeter scaling with a logarithmic term associated with the Luttinger liquid parameter K. This effective Luttinger liquid parameter K reflects the low-energy physics and CFT for (1+1)D surface. At bulk critical point, the effective K is suppressed but it keeps finite value, indicating the coupling between the gapless edge state and bulk fluctuation. The logarithmic term numerically captures this coupling picture, which reveals the (1+1)D SU(2)1 CFT and (2+1)D O(3) CFT at surface criticality. Our work paves a new way to study the exotic surface state and surface criticality.

报告人简介：

      王艳成， 2013年在北京师范大学物理系取得博士学位，之后在中科院物理所从事博士后研究，2017年加入中国矿业大学材料与物理学院，2022年加入北航杭州国际创新研究院（学院）。主要从事量子多体系统中新奇量子相与量子相变的研究，已在Nat. Commun.、Phys. Rev. Lett. 等国内外著名学术期刊上发表学术论文30余篇。主持国家自然科学基金青年及面上项目、浙江省自然科学基金重点项目等课题。主讲《大学物理》、《力学》等课程。