Chiral Damping in Two-Dimensional Materials/Ferromagnet Heterostructures

The use of chiral spintronics, founded upon chiral magnetic structures, holds particular promise for the prospective development of devices that exhibit enhanced performance and functionalities. While much of the chirality in such systems has traditionally been linked to the Dzyaloshinskii–Moriya interaction (DMI), recent theoretical and experimental developments suggest that chirality can also manifest in energy dissipation processes. In this work, we report on experimental observation of the chiral damping phenomenon involving heterostructures combining 2D and ferromagnetic materials, namely WTe 2 /Permalloy (Py) and PtTe 2 /Py based systems. This effect was revealed through an analysis of the line width asymmetry in the Brillouin light scattering spectra, which reflects the dissipation characteristics of counter-propagating spin waves. Interestingly, while no measurable value was observed for the DMI, the existence of chirality associated with the damping is experimentally established. Therefore, we were able to directly quantify chiral damping and demonstrate that interface is a key parameter.