Direct measurement of interfacial Dzyaloshinskii-Moriya interaction at the MoS2/Ni80Fe20 interface

We report on a direct measurement of sizable interfacial Dzyaloshinskii-Moriya interaction (iDMI) at the interface of two-dimensional transition metal dichalcogenide (2D-TMD), MoS 2 and Ni 80 Fe 20 (Py), using Brillouin light scattering spectroscopy. A clear asymmetry in spin-wave dispersion is measured in MoS 2/Py/Ta, while no such asymmetry is detected in the reference Py/Ta system. A linear scaling of the DMI constant with the inverse of Py thickness indicates the interfacial origin of the observed DMI. We further observe an enhancement of DMI constant in a three to four layer MoS 2/Py system (by 56%) as compared to that in two layer MoS 2/Py, which is caused by a higher density of MoO 3 defect species in the case of three to four layer MoS 2. The results open possibilities of spin-orbitronic applications utilizing the 2D-TMD-based heterostructures.