Proximity-induced spin-orbit coupling in graphene offers an exciting platform to probe spin-based effects in chiral Dirac fermionic systems. These systems are believed to be intrinsically time-reversal symmetric, which should ensure that the charge Hall response vanishes without a magnetic field. In contrast to this expectation, we report the first observation of anomalous Hall effect (AHE) in single-layer graphene/single-layer WSe2 heterostructures that persists up to room temperature. The magnitude and the sign of the AHE can be tuned using an external perpendicular electric field. Our joint experimental and theoretical study establishes that the observed anomalous Hall signal arises from the combined effect of strain and spin-orbit coupling in graphene, which induces time-reversal symmetry breaking and manifests as a valley asymmetry. Our observation broadens the prospects of realizing high-temperature anomalous Hall effects in a completely new system, namely graphene-transition metal dichalcogenide-based heterostructures.
Published in: "arXiv Material Science".