Fachgruppe Nanostrukturierte Materialien    

It is shown that when spin-polarized electrons are injected from a (Zn,Be,Mn)Se spin-aligner into GaAs, the magneto-optical Kerr effect from (Zn,Be,Mn)Se/GaAs spintronic device is strongly affected by a large electric-field at the (Zn,Be,Mn)Se/GaAs interface. This field causes the magneto-optical signal to be extremely sensitive to the sample temperature and the wavelength of the probing light. The observed temperature dependencies are explained in terms of the Franz-Keldysh effect at (Zn,Be,Mn)Se/GaAs interface. The findings demonstrate that the results of magneto-optical detection of electrically injected spins in spintronic devices can be easily misinterpreted if electric-field induced effects are not taken into account.