Quantum Hall stripes in high-density GaAs/AlGaAs quantum wells

We report on quantum Hall stripes (QHSs) formed in higher Landau levels of GaAs/AlGaAs quantum wells with high carrier density (ne>4×1011cm-2) which is expected to favor QHS orientation along the unconventional 110 crystal axis and along the in-plane magnetic field B. Surprisingly, we find that at B=0 QHSs in our samples are aligned along the 110 direction and can be reoriented only perpendicular to B. These findings suggest that high density alone is not a decisive factor for either abnormal native QHS orientation or alignment with respect to B, while quantum confinement of the 2DEG likely plays an important role.