Using laser to trigger a large positive magnetoresistive effect in nonmagnetic Si-based metal-oxide-semiconductor structure

A colossal positive magnetoresistive effect triggered by a laser was observed in a nonmagnetic Si-based metal-oxide-semiconductor structure. The positive magnetoresistance was greatly promoted compared to the case with no laser illumination. In addition, it shows high sensitivity to the magnetic field intensity above a certain threshold at room temperature, making it an appealing candidate for magnetic field detection. Moreover, the magnetoresistance can be regulated by the position of laser beams, which enables us to tailor the devices to meet various needs. We attribute this effect to the anisotropy of the carrier transport characteristics in our structure. The work suggests a different approach to develop laser-controlled magnetic devices and may greatly improve the performance of existing magnetoresistance-based devices. Published by AIP Publishing.