时间：9月12日（周五）9：00

地点：勤园20-518

报告简介：

When the transverse-field Ising chain (TFIC) at its quantum critical point is perturbed by a longitudinal field along Ising spin direction, it emerges as an integrable model containing eight particles with their scattering matrices and mass spectrum organized by the exceptional E8 Lie algebra. If it weakly couples with the other quantum critical Ising chain but without the longitudinal field, then the weak inter-chain coupling can drive the system to emerge as another integrable model with eight particles, organized by the Lie algebra. Either way, realizing the quantum criticality of the TFIC is a key step to access the two exotic integrable systems. In my talk, I will explore the quantum criticality of the TFIC and its role in identifying materials hosting TFIC quantum criticality and exotic E8 physics. My journey began with an inelastic neutron scattering experiment on CoNb2O6, sparking my exploration of E8 physics. Despite a ten-year gap, recent THz spectroscopy on the same material reignited my interest, leading us to challenge the E8 paradigm and propose the  picture. I will discuss why the  physics provides a comprehensive understanding for the experimental observations. Along the course, we also surprisingly found long-life-time dark particle, a special kind of many-body magnetic excitation, in the integrable system which accommodates the physics.  

报告人简介 ：

吴建达，李政道学者。长期致力于量子相变、量子临界热力学及动力学、贝特拟设及可积系统动力学等相关领域的研究工作。2004年及2007年于中国科学技术大学获得学士及硕士学位、2014年博士毕业于美国莱斯大学、2014-2017年在美国加州大学圣地亚哥分校从事博士后工作、2017-2018年担任德国马普复杂系统物理所客座研究员。2018年至今就职于上海交通大学李政道研究所及物理与天文学院。迄今已在包括PRL、Nature及Nature子刊、Science Bulletin等在内的高水平学术期刊上共发表论文三十余篇。获批2025年国家自然基金原创探索项目。先后在国内外重要学术会议、学术机构及单位给邀请学术报告八十余次。专长：量子相变、量子临界热力学及动力学、Bethe Ansatz、量子可积场论、量子多体动力学。