Magnon-polaron driven thermal Hall effect in a Heisenberg-Kitaev antiferromagnet
N. Li, Robin R. Neumann, Shuangkui Guang, Qing Huang, Jian Liu, Ke Xia, Xiaoyu Yue, Y. Sun, Yiyan Wang, Q. J. Li, Yuxuan Jiang, Jiyuan Fang, Zhigang Jiang, Xinguo Zhao, Alexander Mook, Jürgen Henk, Ingrid Mertig, Haidong Zhou, X. F. Sun
Abstract
The thermal Hall effect, where a transverse heat current is generated in response to a longitudinal temperature gradient, probes charge-neutral excitations in insulating quantum matter. By studying thermal transport in the Heisenberg-Kitaev antiferromagnet and spin liquid candidate Na${}_{2}$Co${}_{2}$TeO${}_{6}$, the authors find here that magnon polarons, i.e., hybridized phonons and magnons produced by spin-lattice coupling, govern the sign and magnitude of the observed signal. This is in contrast to a pure magnon transport theory, which fails to capture important features of the experiment.