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

Abstract

We report on quantum Hall stripes (QHSs) formed in higher Landau levels of GaAs/AlGaAs quantum wells with high carrier density ($n_e>4\times 10^{11}$ cm${}^{-2}$) which is expected to favor QHS orientation along unconventional $⟨1\bar{1}0⟩$ crystal axis and along the in-plane magnetic field $B_{||}$. Surprisingly, we find that at $B_{||}=0$ QHSs in our samples are aligned along $⟨110⟩$ 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.

4 pages