Y. D. Gu

Photon‐Gated Spin Transistor

A new type of spin transistor with an optical gate is proposed with partial exposure of the device, where spin scattering is enhanced under light illumination due to the photon-induced minor spins. Consequently a reproducible transient gate operation of reisitance via optical methods is observed, as ascribed to the nature of spin excitation.

Magnetoresistance flipping of Fe∕Ru multilayers prepared by electron-beam evaporation

Fe∕Ru multilayers were prepared by electron-beam evaporation. The magnetoresistance (MR) properties of the multilayer switched the MR sign with the Fe and Ru layer thickness. When the thickness of magnetic Fe layers was fixed at 1.2 nm, the MR effects of the multilayer transformed from a negative to a positive one, with the thickness of nonmagnetic Ru layer changed from 1.2 to 5.0 nm. While when the thickness of nonmagnetic Ru layers was fixed, the transformation of the MR effect is inversed, i.e., transformed from a positive to a negative one with the thickness of the magnetic Fe layer increased. The origin of the MR variation is analyzed. The inverse giant magnetoresistance is related to the Fe∕Ru interface layer, in which the scattering spin asymmetry is less than 1. The MR dependence on the Fe and Ru layer thickness reveals the competition between two mechanisms of normal MR and inverse MR