Generation of half-integer harmonics and efficient THz-to-visible frequency conversion in strained graphene

We study the generation of harmonics from graphene under influence an artificial magnetic field, generated via bending a flake. show how Landau level structure induced by pseudomagnetic field breaks centrosymmetry graphene, thus allowing even harmonics. also that depending on impinging pulse duration, nonlinear signal does not only contain integer but its half-integer ones due to peculiar square-root-like nature levels in graphene.