Stray fields of iron electrodes for spin-polarized transport

In semiconductor spintronic devices that incorporate ferromagnetic materials the stray-field configuration in the plane of the two-dimensional electron system is of crucial importance. We investigate the stray fields of iron electrodes suitable as injector and detector for spin-polarized transport in hybrid semiconductor/ferromagnet devices. Magnetic-force microscopy images of an electrode pair are derived from simulated magnetization patterns. The calculated averaged stray field is compared to the experimental signal of a ballistic Hall micromagnetometer comprising a two-dimensional electron system in a GaAs/AlGaAs-heterostructure 90 nm below the electrodes. Good agreement between simulation and experiment is obtained.