【报告题目】：Diagnosing strong-to-weak symmetry breaking via Wightman correlators
【报 告 人】：刘泽宇（博士后，复旦大学）
【报告地点】：29-414
【报告时间】：12月8日（星期一）14:00
【报告摘要】：Symmetry plays a fundamental role in quantum many-body physics, and a central concept is spontaneous symmetry breaking. Recent developments highlight new symmetry-breaking patterns known as strong-to-weak spontaneous symmetry breaking, characterized by two different order parameters: the fidelity correlator and the Rényi-2 correlator which are inequivalent. In this work, we propose the Wightman correlator as an alternative diagnostic tool. This construction relies on the introduction of the thermofield double state for a generic density matrix, which maps the strong symmetry of the density matrix to the doubled symmetry of the pure state, allowing the Wightman correlator to emerge naturally as a standard probe of symmetry breaking. We prove the equivalence between the Wightman correlator and the fidelity correlator, and examine explicit examples. The validity of Wightman correlator has wide applications for understanding strong-to-weak spontaneous symmetry breaking.
参考文献：Zeyu Liu, Langxuan Chen, Yuke Zhang, Shuyan Zhou & Pengfei Zhang. Diagnosing strong-to-weak symmetry breaking via Wightman correlators. Communications Physics 8, 274 (2025).
【报告人简介】：刘泽宇，2021年本科毕业于华东师范大学物理与电子科学学院，现为复旦大学张鹏飞青年研究员在读博士研究生。研究方向包括量子多体系统中的信息弥散动力学，开放量子系统。目前已以第一作者身份在Physical Review Letters等期刊发表SCI论文3篇，同时有一篇arXiv预印本。
