The development of a micro-coil-on-ASIC type GSR sensor driven by GHz pulse current

Through applying GHz (Gigahertz) pulse current on the amorphous micro wire, we observed an increase in the coil voltage around the wire, and a sine function relationship between the coil voltage and the surrounding magnetic field. We assumed that the new performance of the coil voltage must be caused by the rotation of electron spins on the wire surface with GHz angular velocity, induced by the magnetic field force in the same direction, and proposed to name the observed new phenomena as GSR (Gigahertz Spin Rotation) effect. The developed GSR sensor presents excellent features with enhanced sensitivity and low hysteresis better than that of the GMI (Giant Magnetoimpedance) sensor. We developed the production technology to produce micro coils and developed a Micro-coil-on-ASIC (Application Specified Integrated Circuit) type GSR sensor, where the micro coils are directly formed on the ASIC surface, making small size GSR sensor possible.