Highly tunable nonlinear Hall effects induced by spin-orbit couplings in strained polar transition-metal dichalcogenides

Recently, signatures of nonlinear Hall effects induced by Berry curvature dipoles have been found in atomically thin 1Td-WTe2. In this work, we show that in strained polar transition-metal dichalcogenides(TMDs) with 2H-structures, Berry curvature dipoles created by spin degrees of freedom lead to strong nonlinear Hall effects. Under accessible applied strains, the Berry curvature dipole in electron-doped polar TMDs such as MoSSe is in the order of 1 Angstrom which is easily detectable experimentally. Moreover, the magnitude and sign of the Berry curvature dipole in strained polar TMDs can be easily tuned by electric gating and strain. These properties can be used to distinguish nonlinear Hall effects from other effects such as ratchet effects. Importantly, our system provides a promising scheme for realising electrically switchable energy harvesting rectifiers.