Coupled spin Hall effect of ferrite/feromagnetic bilayer films and detection of microwave electromagnetic fields

Designing novel spin-wave heterojunction materials and regulating their magnetic properties are key technologies for realizing spin quantum detection of microwave electromagnetic fields. In this study, a spin-wave heterojunction microwave electromagnetic field sensing detection scheme has been proposed, which modifies the inverse spin Hall effect (ISHE) by manipulating the magnetic moment distribution, anisotropic crystal field and ferromagnetic resonance line width (\Delta H) of ferrite/ferromagnetic bilayer films. Then, the nanocrystalline DyCoNbZr/Bi_1Dy_2Fe_5O_12 bilayer films and the spin-wave heterojunction Pt/DyCoNbZr/Bi_1Dy_2Fe_5O_12 were fabricated, and the effects of damping-like torque, field-like torque, and the ferrite underlayer on the magnetization distribution of the spin-wave heterojunction were analyzed. The results show that the excited microwave electromagnetic field signal can be detected with high sensitivity by inverse spin Hall voltage (V_\rm ISHE) detection of the spin wave heterojunction, and the V_\rm ISHE is directly related to the amplitude, frequency, and phase of the microwave electromagnetic field. The spin-orbit interaction between the Bi_1Dy_2Fe_5O_12 and DyCoNbZr films can enable the films with low saturation magnetization to undergo an ISHE at low microwave excitation power, which lays a technical foundation for detecting the microwave electromagnetic fields using the ISHE.