Electrical spin manipulation with Al2O3 gate insulator in InGaAs based mesoscopic ring arrays

We demonstrated gate controlled spin precession in InGaAs based mesoscopic ring arrays. We applied two different gate insulators, Al2O3 and SiO2, to compare the gate sensitivity for the spin precession. Al’tshuler–AronovSpivak (AAS) oscillations were clearly observed and the resistance amplitude of AAS oscillations at zero magnetic field depends on the gate voltage. The spin precession angle of 2π is achieved by the gate voltage of 5.4 V for SiO2 gate insulator and 0.6 V for Al2O3 gate insulator. Al2O3 gate is effective for electrical spin manipulation and enables the spin manipulation in a wide range.