Signature of Hanle Precession in Trilayer MoS2: Theory and Experiment

Valley-spin coupling in transition-metal dichalcogenides (TMDs) can result in unusual spin transport behaviors under an external magnetic field. Nonlocal resistance measured from 2D materials such as TMDs via electrical Hanle experiments are predicted to exhibit nontrivial features, compared with results from conventional materials due to the presence of intervalley scattering as well as a strong internal spin-orbit field. Here, for the first time, we report the all-electrical injection and non-local detection of spin polarized carriers in trilayer MoS_2 films. We calculate the Hanle curves theoretically when the separation between spin injector and detector is much larger than spin diffusion length, \lamda_s. The experimentally observed curve matches the theoretically-predicted Hanle shape under the regime of slow intervalley scattering. The estimated spin life-time was found to be around 110 ps at 30 K.