Measurements of composite fermion conductivity dependence on carrier density

Abstract

We present the first experimental study of the carrier density dependence of the composite fermion conductivityσxxCF at Landau levelfilling factors ν = 1/2 and3/2 in high-quality front-gatedGaAs/Al0.33Ga0.67As heterostructures.Extracting α from the power law shows that . The measured is placed between the predicted value3/4 in the strong random magnetic field regime, and3/2 in the weak random magnetic field regime. Comparisons between our results and theory arediscussed.