Giant effect of spin-lattice coupling on the thermal transport in two-dimensional ferromagnetic CrI₃

Recently, two-dimensional monolayer chromium triiodide (CrI3) with intrinsic magnetism was discovered, which shows promising applications in many technologies from sensing to data storage where thermal transport play a key role. So far the effect of spin-lattice coupling on the thermal transport properties has not been explored yet. In this talk, I would like to present the giant effect of spin-lattice coupling on the thermal conductivity of monolayer CrI3. The thermal conductivity is more than two orders of magnitude enhanced by the spin-lattice coupling. The effect is found to be especially stronger for the acoustic phonon modes, which dominates thermal transport with spin-lattice coupling. Deep analysis shows that the reason lies in the weakened phonon anharmonicity by spin-lattice coupling. The bond angle and atomic position are changed due to the spin-lattice coupling, making the structure more stiff and more symmetric, which lead to the weaker phonon anharmonicity, and thus the enhanced thermal conductivity. This study uncovers the giant effect of spin-lattice coupling on the thermal transport, which would deepen our understanding on thermal transport and shed light on future research of thermal transport in magnetic materials.