Control of the Magnetostatic Stray Fields Using Electric Current

Abstract

Possibility to control magnetic stray fields around conductive layered ferromagnet-containing systems has been analyzed. It is shown that different patterns of magnetic stray field can be realized depending on layers parameters and current. Calculation is based on the simplified model where the real stray field is approximated with that of effective magnetic charges at the sample surface. In case of in-plane magnetization the induced stray field partially screens the external one. This screening is less effective when the applied magnetic field is replaced with electric current. In case of out-of-plane magnetization the stray field is concentrated near domain walls and near sample edges where it can be extremely strong. The mechanism to control different components of the stray field via domain wall rotation by current-induced magnetic field is proposed. Numerical estimation shows that expected ratio of stray field to current is close to experimental values obtained in numerous transport measurements and usually ascribed to proximity effects (exchange interaction between carriers in adjacent layers). The proposed alternative origin of effective field should be taken into account dealing with spin Hall effect and similar spintronics problems.