Optical magnetoelectric effect of patterned oxide superlattices with ferromagnetic interfaces

Nonreciprocal directional dichroism, termed the optical magnetoelectric (OME) effect, has been observed in patterned superlattice (SL) composed of perovskite oxides, LaMnO3, SrMnO3, and LaAlO3. Such a tricolor SL with ferromagnetic interfaces is expected to artificially break both space-inversion and time-reversal symmetries and hence to show the OME effect. The Bragg diffraction from the grating structure with a period of 4 mu m fabricated on the SL was employed to sensitively detect the OME effect, yielding the relative change of the diffracted light intensity (similar to 0.2%-0.5%) upon a reversal of either the in-plane magnetization or the propagation vector of the diffracted light.