  The magnetic Laplacian with a step magnetic field has been intensively
studied during the last years. We adapt the construction introduced by
Bonnaillie-No\"el, Fournais, Kachmar and Raymond to prove the existence of
bound states of a new effective operator involving a magnetic step field on a
domain with an almost flat magnetic barrier. This result emphasizes the fact
that even a small non-smoothness of the discontinuity region can cause the
appearance of eigenvalues below the essential spectrum. We also give an example
where this effective operator arises.
