主讲人：廖海军 副研究员（中国科学院物理研究所）

题目：Spin Excitation Spectra of Anisotropic Spin-1/2 TriangularLattice Heisenberg Antiferromagnets

时间：2024年7月31日（周三）下午15：00

腾讯ID: 842 218 914

地 点：理工楼1215

联系人：赵继泽 教授

报告摘要：

Investigation of dynamical excitations is difficult but crucial to the understanding of many exotic quantum phenomena discovered in quantum materials. This is particularly true for highly frustrated quantum antiferromagnets whose dynamical properties deviate strongly from theoretical predictions made based on the spin-wave or other approximations. Here we present a large-scale numerical calculation on the dynamical correlation functions of spin-1/2 triangular Heisenberg model using a state-of-the-art tensor network renormalization group method. The calculated results allow us to gain for the first time a comprehensive picture on the nature of spin excitation spectra in this highly frustrated quantum system. It provides a quantitative account for all the key features of the dynamical spectra disclosed by inelastic neutron scattering measurements for Ba₃CoSb₂O₉, revealing the importance of the interplay between low- and high-energy excitations and its renormalization effect to the low-energy magnon bands and high-energy continuums. We identify the longitudinal Higgs modes in the intermediate-energy scale and predict the energy and momentum dependence of spectral functions along the three principal axes that can be verified by polarized neutron scattering experiments. Furthermore, we find that the spin excitation spectra weakly depend on the anisotropic ratio of the antiferromagnetic interaction.

个人简介：

廖海军，中国科学院物理研究所副研究员，博士生导师。2009年中国人民大学学士， 2014年中国人民大学博士。2014年-2017年，在中国科学院物理研究所从事博士后研究。2017年-至今，在中科院物理所工作，2023年获得国家青年人才项目资助。主要研究兴趣是发展新的张量重正化群方法，并运用它研究阻挫磁性等强关联系统，以及各种经典统计模型等。至今在PRL、PRX等国际一流期刊发表论文多篇。