Large magnetoresistance in square-shaped hybrid magnet-semiconductor device

Abstract

We have obtained large positive and negative magnetoresistance in a square-shaped InAs two-dimensional electron gas in which the magnetoresistance is controlled by the magnetization of a ferromagnetic gate on the surface of the device. From an analysis based on a numerical calculation, the mechanism of this effect can be understood in terms of a spatially varying Hall conductivity and a geometrical effect of the device. This device has several practical advantages over the device with extraordinary magnetoresistance reported by Solin et al.