Gate controlled hall effect devices

Abstract

A novel active magnetoelectronic device consisting of a ferromagnetic film and gate electrodes on a GaAs/AlGaAs heterostructure has been fabricated and characterized. Magnetization of the ferromagnetic film is manipulated by external magnetic field which is applied in parallel to the ferromagnetic film axis. Magnetic fringe field at the edge of the ferromagnetic film gives rise to the Hall voltage, which shows hysteretic behavior upon magnetic field sweep. When negative voltage is applied to the gate electrodes, the Hall voltage has increased dramatically. The Hall voltage can be amplified by a factor more than 200.