Noncollinear magnetoresistance of trilayers consisting of two ferromagnetic GaMnAs layers and a nonmagnetic GaAs:Be spacer

Abstract

The magnetotransport properties of a GaMnAs trilayer in which two GaMnAs layers are separated by a nonmagnetic GaAs:Be spacer has been investigated during the magnetization reversal process. Interestingly, the planar Hall resistance (PHR) reveals that the two GaMnAs layers in a trilayer structure have opposite signs of anisotropic magnetoresistance (AMR). The magnetoresistance is observed to be significantly different for the collinear and noncollinear magnetic alignment, which indicates that the presence of the giant magnetoresistance (GMR)-like effect in the system. This GMR-like effect was systematically investigated during the process of magnetization reversal using field and angle scans of MR measurements.