Effect of density on quantum Hall stripe orientation in tilted magnetic fields

We investigate quantum Hall stripes under an in-plane magnetic field B in a variable-density two-dimensional electron gas. At filling factor ν=9/2, we observe one, two, and zero Binduced reorientations at low, intermediate, and high densities, respectively. The appearance of these distinct regimes is due to a strong density dependence of the...

Microwave-induced resistance oscillations in a back-gated GaAs quantum well

We performed effective mass measurements employing microwave-induced resistance oscillation in a tunable-density GaAs/AlGaAs quantum well. Our main result is a clear observation of an effective mass increase with decreasing density, in general agreement with earlier studies which investigated the density dependence of the effective mass...