郭浩宇 | Resonant thermal Hall effect of phonons coupled to dynamical defects

<注:本视频仅用于学术交流,版权归报告人所有>

 

►【理论室报告

报告人:郭浩宇(Harvard University)
报告时间:2022年8月15日(星期一)下午15:00​​​​​​​
会议地点: 线上/中科院物理研究所M楼830会议室

报告摘要:Recent thermal transport measurements in various materials including pseudogap cuprates have observed large thermal Hall effects which are attributed to phonons. In this talk, I will review some recent experiments and propose a theory of phonon thermal Hall effect based on resonant scattering of phonons off dynamical defects. Using a microscopic formulation based on the Kubo formula, we find that the leading contribution perturbative in the phonon-defect coupling is proportional to the phonon lifetime. This contribution is at resonance when the phonon energy equals a defect level spacing. Our results are obtained for different defect models, and include a model of an impurity quantum spin in the presence of quasi-static magnetic order with an isotropic Zeeman coupling to the applied field, which we propose applies to the cuprate pseudogap regime.