Schematic of the nonlinear Hall effect (IMAGE) Science China Press Caption In small-angle twisted bilayer WSe2, finite strain results in nonzero Berry curvature dipole D. An AC signal E injected from the source to the drain, the nonzero dipole results in a second-harmonic nonlinear Hall signal j2 . Credit ©Science China Press Usage Restrictions Use with credit. License Original content Disclaimer: AAAS and EurekAlert! are not responsible for the accuracy of news releases posted to EurekAlert! by contributing institutions or for the use of any information through the EurekAlert system.