Controlled GMR enhancement from conducting inhomogeneities in non-magneticsemiconductors

We report results of magneto-transport studies of homogeneous, high-mobilit y, Te-doped InSb in a thin film van der Pauw disk geometry (radius r(b)) co ntaining a lithographically patterned, concentric, cylindrical metallic inh omogeneity (radius r(a)). The room temperature giant magnetoresistance (GMR ) increases dramatically with increasing r(a). We show that the GMR enhance ment could in principle be made far larger by optimizing the material selec tion and lithographic patterning. We also discuss the potential impact of o ur results on read-head devices in high-density recording and on other magn etic sensors. (C) 2000 Elsevier Science B.V. All rights reserved.