Huge positive magnetoresistance in a gated AlGaAs/GaAs high electron mobility transistor structure at high temperatures

Abstract

Magnetoresistivity measurements on a gated AlGaAs/GaAs high electron mobility transistor (HEMT) structure were performed at high temperatures T. By changing the applied gate voltage V(g), we can investigate the observed huge positive magnetoresistance (PMR) at different effective disorder and density inhomogeneity within the same HEMT structure. The observed PMR value increases with increasing disorder in the depletion mode (V(g)<= 0). Moreover, the PMR value is not limited by the quality of the HEMT structure at T=80 K. Such results pave the way for low-cost, high-throughput GaAs-based HEMT fabrication for future magnetic sensing and recording devices fully compatible with the mature HEMT technology. (C) 2008 American Institute of Physics.