Extrinsic spin-orbit coupling induced enhanced spin pumping in few-layer MoS2/Py

We report on broadband ferromagnetic resonance spectroscopy studies of permalloy (Py) thin films grown on large area pulse laser deposited MoS2. We observe an enhancement of the effective damping constant of the Py layer grown on few-layer MoS2. The spin mixing conductance is found to be an order of magnitude larger in the case of 3.5 (average of the 3-4 layer)-layer-MoS2/Py compared to the case of 2-layer-MoS2/Py. The results are interpreted as a consequence of the extrinsic defect induced spin-orbit coupling at the 3.5-layer-MoS2/Py interface evidenced by a higher variation of Raman intensity across the sample as compared to the 2-layer-MoS2/Py system.