演讲人： Haoyu Guo Harvard University
时间： 2022-08-16 15:00-2022-08-16 16:00
地点：Conference Hall 104, Science Building, Tsinghua University
内容：

Recent thermal transport measurements in various materialsincluding 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.