Quantum hall effect and hopping conduction in InxGa1−xAs-InP heterojunctions at low temperature

Abstract We report investigations of the temperature dependence of the quantum Hall effect in modulation doped In x Ga 1− x As-InP heterojunctions. The diagonal conductivity σ xx is studied at several minima of the magneto-resistance ϱ xx between 50 mK and 2 K. A hopping conduction mechanism is observed when the Fermi level is in the tail of the Landau levels.