Huge positive magnetoresistance of GaAs∕AlGaAs high electron mobility transistor structures at high temperatures

Abstract

The authors have performed magnetoresistivity measurements ρxx(B) on GaAs∕AlGaAs high electron mobility transistor (HEMT) structures at high temperatures T. These HEMT structures show huge positive magnetoresistance (MR). For B=±6T, the MR values are >1300% and >200% at T=20 and 80K, respectively. Since a GaAs-based HEMT structure is not susceptible to ferromagnetic noise which appears to represent a fundamental challenge to the scalability of magnetic MR devices to ultrahigh area densities, the experimental results pave the way for the integration of scalable nonmagnetic MR devices with the mature HEMT technology using the same material system.