We report the observation of a reentrant quantum Hall state at the Landau level filling factor nu = 1 in a two-dimensional hole system confined to a 35-nm-wide (001) GaAs quantum well. The reentrant behavior is characterized by a weakening and eventual collapse of the nu = 1 quantum Hall state in the presence of a parallel magnetic field component B||, followed by a strengthening and reemergence as B|| is further increased. The robustness of the nu = 1 quantum Hall state during the transition depends strongly on the charge distribution symmetry of the quantum well, while the magnitude of B|| needed to invoke the transition increases with the total density of the system.
@article{arxiv.1109.3808,
title = {Reentrant nu = 1 quantum Hall state in a two-dimensional hole system},
author = {A. L. Graninger and D. Kamburov and M. Shayegan and L. N. Pfeiffer and K. W. West and K. W. Baldwin and R. Winkler},
journal= {arXiv preprint arXiv:1109.3808},
year = {2012}
}