Detecting spin polarization in 2D MoSe2 with nitrogen vacancy centers in diamond

Since the isolation of monolayer graphene, the catalog of exfoliatable two dimensional materials has grown to include materials with a host of properties, including semiconductors, ferromagnets, and even superconductors. Of particular interest are the transition metal dichalcogenides (TMDCs), which in the monolayer limit are direct band gap semiconductors that support tightly bound excitons. Due to spin orbit coupling and a lack of inversion symmetry, spins in the two inequivalent K valleys are polarized, which has led to great interest in TMDCs for spin- and valley-tronic applications. While the spin properties of TMDCs have been studied with optical techniques, these offer limited spatial resolution and are difficult to extract quantitative values from. We report on progress towards the measurement of optically induced spin polarization in hole doped MoSe2 using nitrogen vacancy centers in diamond as nanoscale magnetic field probes. The close proximity of these sensors, coupled with available superresolution techniques, will enable nanoscale imaging and quantification of other exotic phenomena in TMDs such as the valley hall effect and imaging of Moire superlattice TMDC structures.