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