Title: On-demand higher-harmonic generation through nonlinear Hall effects in curved nanomembranes

Abstract: The high-order Hall effects, which go beyond the ordinary, unlock more possibilities of electronic transport properties and functionalities. Pioneer works focus on the manufacture of complex nanostructures with low lattice symmetry to produce them. In this paper, we theoretically show that such high-order Hall effects can alternatively be generated by curving a conducting nanomembrane which is highly tunable and also enables anisotropy. Its Hall response can be tuned from first to fourth order by simply varying the direction and magnitude of the applied magnetic field. The dominant Hall current frequency can also be altered from zero to double, or even four times that of the applied alternating electric field. This phenomenon is critically dependent on the occurrence of high-order snake orbits associated with the effective magnetic-field dipoles and quadruples induced by the curved geometry. Our results offer pathways for spatially engineering magnetotransport, current rectification, and frequency multiplication in the bent conducting nanomembrane.