Temperature Dependence of Magnetotransport in Extraordinary Magnetoresistance Devices

Abstract

Extraordinary magnetoresistance (EMR) devices have been fabricated and characterized at various magnetic fields, operating temperatures, and current excitations. These devices are comprised of nonmagnetic high mobility semiconductors and low resistance metallic contacts and shunts. The resistance of the device is modulated by magnetic fields due to the Lorentz force steering an electron current between the high resistance semiconductor and the low resistance metallic shunt. The EMR devices were tested between 300 K and 5 K in magnetic fields up to 2 T perpendicular to the 2DEG plane and excitation currents up to 100 <tex xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">$mu$</tex> A. Magnetoresistance increases as temperature decreases, potentially indicating that EMR persists even as dimensions approach the electron mean free path.