Zusammenfassung

We present a magnetooptical study of the energy spectrum of two-dimensional electrons subjected to a perpendicular magnetic field in the presence of a square lattice of antidots. We demonstrate that commensurability features in the luminescence intensity can be observed below the Fermi energy leading to a quadratic dependence of their spectral positions on the applied magnetic field. The possible origin of this novel effect will be discussed by comparing with model calculations.