吴建达 副教授学术报告
Title: Spin dynamics and dark particles in a weak-coupled quantum Ising ladder with D8 spectrum
Speaker: Jianda Wu (吴建达)
Affiliation: Shanghai Jiao Tong Universtiy（上海交通大学）
Time: 14:00-15:00, Wednesday, 14th August, 2024 (UTC+8, Beijing Time)
Venue: Room 1502, Shing-Tung Yau Center, Yifu Architecture Building, Sipailou Campus of Southeast University, Nanjing
（东南大学四牌楼校区逸夫建筑馆丘成桐中心1502室）
Inviter: Yunfeng Jiang （江云峰）
Abstract
When two quantum critical transverse-field Ising chains (TFIC) are weakly coupled, the weak inter-chain coupling can drive the system to emerge as an integrable model with eight particles, organized by the D8 Lie algebra [1]. Realizing the quantum criticality of the TFIC is a key step to access the exotic integrable system. In my talk, after first exposing the quantum criticality of the TFIC [2 - 4], I will begin my journey with an inelastic neutron scattering experiment on CoNb2O6, which claims observation of evidence of E8 physics in the material [5]. Despite a ten-year gap, recent THz spectroscopy on the same material [6] reignited our interest, leading us to challenge the E8 paradigm and propose the D8 picture. I will discuss why the D8 physics provides a comprehensive understanding for the experimental observations [7]. 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 D8 physics [8]. We will discuss how the dark particles are able to be prepared via another exotic soliton excitations in the system, and further propose a thermal activation detection of the lightest dark particle [9].
[1] A. LeClair, A.W.W. Ludwig, G. Mussardo, Nucl. Phys. B 512, 523 (1998).
[2] Jianda Wu, Lijun Zhu and Qimiao Si, Phys. Rev. B 97, 245127 (2018).
[3] Zhe Wang*, T. Lorenz*, D. I. Gorbunov, P. T. Cong, Y. Kohama, S. Niesen, O. Breunig, J. Engelmayer, A. Herman, Jianda Wu*, K. Kindo, J. Wosnitza, S. Zherlitsyn, and A. Loidl, Phys. Rev. Lett. 120, 207205 (2018).
[4] Haiyuan Zou, Rong Yu*, Jianda Wu*, J. Phys.: Condens. Matter. 32, 045602 (2020).
[5] R. Coldea, et al. Science, 327, 177 (2010).
[6] K. Amelin, et al. Phys. Rev. B 102, 104431 (2020).
[7] N. Xi#, X. Wang#, Y. Gao, Y. Jiang, R. Yu*, J. Wu*, arXiv: 2403.10785.
[8] Y. Gao, X. Wang, N. Xi, Y. Jiang, R. Yu*, J. Wu*, arXiv: 2402.11229.
[9] Y. Gao#, J. Yang#, H. Lin, R. Yu, J. Wu*, arXiv: 2406.15024.
#: co-first author; *: corresponding author
Speaker
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子刊等在内的高水平学术期刊上共发表论文三十余篇。先后在国际及国内重要学术会议、科研机构及学术单位给邀请学术报告六十余次。