Large tunneling magnetoresistance in a field-effect transistor with a nanoscale ferromagnetic gate

Abstract

We demonstrate large, and hysteretic, tunneling magnetoresistance (MR) in field-effect transistors (FETs), when their usual nonmagnetic gate is replaced with a nanoscale ferromagnet. Our analysis indicates that the enhanced MR in the tunneling regime results from the ability of the fringing magnetic fields, which emanate from the nanomagnet into the FET channel, to provide an additional modulation of the electrostatic barrier induced by the applied gate voltage. The ability of this device to detect changes in magnetization may eventually allow the implementation of reprogrammable devices for universal logic and memory applications.