Magnetotransport properties of GaMnAs with ferromagnetic nanodots

Abstract

The new hybrid device consisting of single array of Co nanodots on top of GaMnAs is presented to explore a new functionality of GaMnAs diluted magnetic semiconductor (DMS). Magnetic state of Co dots was observed by magnetic force microscopy (MFM). Magnetoresistance of pure GaMnAs microbridge strongly depends on the orientation of applied magnetic field. Magnetization reversal of the single domain state definitely affects the longitudinal magnetoresistance of GaMnAs. Inhomogeneous magnetic field induced by Co nanodot is a dominant contribution to the resistance change. This field was regarded to act as an effective potential that may affect the spin polarized carriers in GaMnAs.