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

Abstract

We report on a direct measurement of sizable interfacial Dzyaloshinskii–Moriya interaction (iDMI) at the interface of two-dimensional transition metal dichalcogenide (2D-TMD), MoS2 and Ni80Fe20 (Py), using Brillouin light scattering spectroscopy. A clear asymmetry in spin-wave dispersion is measured in MoS2/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 MoS2/Py system (by 56%) as compared to that in two layer MoS2/Py, which is caused by a higher density of MoO3 defect species in the case of three to four layer MoS2 . The results open possibilities of spin–orbitronic applications utilizing the 2D-TMD-based heterostructures. Partial support from the Ministry of Human Resource Development under the IMPRINT program (Grant Nos. 7519 and 7058), the Department of Electronics and Information Technology (DeitY), and the Science and Engineering Research Board (SERB) under the Core Research Grant (CRG) (Grant No. SERB/F/12383/2018-2019) is gratefully acknowledged. A.B. acknowledges the S. N. Bose National Centre for Basic Sciences for financial assistance under Grant No. SNB/AB/18-19/211. A.K. acknowledges support from the Council of Scientific and Industrial Research (CSIR), India, while A.K.C. acknowledges DST, Government of India, for INSPIRE fellowship (Grant No. IF150922).