Au/GaAs magnetoresistive-switch-effect devices fabricated by wet etching

Au/GaAs magnetoresistive-switch-effect (MRS effect) devices were successfully fabricated by the wet etching method. A large MRS effect was observed. In the current-voltage curves, the current jumped steeply at a threshold voltage of 32.0 V. The threshold voltages shifted to higher values and became less steep with increasing magnetic field. Above 2,000 Oe, no current jump driven by the applied voltage could be observed. The magnetoresistance (MR) ratio reached 1,000,000% at 15,000 Oe when the devices were operated above the threshold voltage. Also magnetic field sensitivity was greatly improved. To achieve a 1000% MR ratio, only 300 Oe was required at 32.2 V.