Resonating magnetoresistance induced by the injection of spin fluctuation

Abstract A nano-scale magnetic sensor, in which magnetic resonance is induced by the injection of spin fluctuation, is proposed. The device is composed of a thin ferromagnetic layer (FM), a non-magnetic layer and a synthetic antiferromagnet (SyAF). Transverse spin fluctuation in conduction electrons, generated by the thermal fluctuation of magnetization in FM, is injected by current into SyAF. The fluctuation induces magnetic resonance in SyAF under an appropriate external field. The increase in resistance by resonance absorption is estimated, assuming the effective-field type interaction in SyAF. Magnetoresistance of more than 100% is expected for a 30 nm ×30 nm device.