Effect of the interface resistance on the extraordinary magnetoresistance of semiconductor/metal hybrid structures

We report on magnetotransport experiments performed at 4.2 K on hybrid structures consisting of a metal and a mesoscopic two-dimensional electron system in an InAs/InGaAs heterostructure. The devices were fabricated using cleaved-edge overgrowth. We find that they exhibit an extraordinary magnetoresistance effect (EMR) which is most pronounced in the case of the lowest specific contact resistance rho(i) of approximate to10(-8)Omega cm(2) achieved in this work. The largest relative resistance change DeltaR/R is 115,000% at a magnetic field B = 1 T. Asystematic study of the performance of the EMR devices with down to sub-mum lateral dimension and with different rho(i) is reported.