Geometry and material optimization of the extraordinary magnetoresistance in the semiconductor-metal hybrid structure

The effects of geometry and material parameters on the extraordinary magnetoresistance (EMR) of the rectangular semiconductor-metal hybrid structure have been studied systematically using the finite-element method (FEM). We find that the EMR depends sensitively on the placement of the voltage probes and explain the origin of the EMR enhancement in the asymmetric voltage probe configuration. The width of the metal is important for the EMR effect as well as the width of the semiconductor. The low-field EMR shows an approximate quadratic with the mobility of semiconductor, while the high-field EMR gradually saturates with the increase of mobility due to the little change of hall angle. To obtain significant EMR effect, the ration of conductivity of metal and semiconductor should be larger than 104