活动主题：Dissipation-induced bulk and boundary criticality in the Haldane chain
活动类型：学术交流
举办单位：物理化学科教中心
活动时间：2026-10-16
活动地点：科研一号楼2126会议室
面向群体：全院师生
主讲嘉宾：
王振九，兰州大学物理科学与技术学院青年研究员。2012年获得山东师范大学学士学位，分别于北京师范大学和德国维尔茨堡大学取得硕士和博士学位先后在德国马克斯普朗克复杂系统物理研究所和慕尼黑大学从事博士后研究工作。自2024年7月于兰州大学任职。研究聚焦于强关联体系中的拓扑物态和非常规量子临界性，提出并数值实现了二维拓扑莫特绝缘体到超导态的解禁闭量子相变，构造了保持连续场论对称性的非线性 Sigma模型无微扰正则化方案。以第一作者发表Phys.RevLett三篇，目前主持在研国家自然科学基金青年科学基金项目(C类)1项，并获得甘肃省高层次海外人才项目资助。
内容摘要：
We study the Haldane chain coupled to a dissipative ohmic bath. Usinglarge-scale quantum Monte Carlo simulations, we identify a second-orderquantum phase transition into an antiferromagnetic state with spontaneouslybroken SO(3) symmetry that is governed by an interacting fixed point withdynamical exponent z≈2. We derive a generalized string order parameterwhich indicates that the symmetry-protected topological ground state of theHaldane chain is stable for weak dissipation and develops a nontrivialscaling dimension at criticality. In particular, its topological edge modesdisplay nontrivial boundary criticality that is distinct from an equivalenttransition out of a trivial state; for the latter, we perform an accurate ϵexpansion of a dissipative ϕ4 theory with ordinary boundary conditions.Our setup realizes a spin impurity in a critical yet nonconformalantiferromagnet and paves the way for continuously tunable boundarycriticality controlled by dissipation.
联系人：物理化学科教中心，王艳成
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