title: Anomalous robustness of the ν=5/2 fractional quantum Hall state near a sharp phase boundary.
abstract: We report magnetotransport measurements in wide GaAs quantum wells with a tunable density to probe the stability of the fractional quantum Hall effect at a filling factor of ν=5/2 in the vicinity of the crossing between Landau levels (LLs) belonging to the different (symmetric and antisymmetric) electric subbands. When the Fermi energy (E(F)) lies in the excited-state LL of the symmetric subband, the 5/2 quantum Hall state is surprisingly stable and gets even stronger near this crossing, and then suddenly disappears and turns into a metallic state once E(F) moves to the ground-state LL of the antisymmetric subband. The sharpness of this disappearance suggests a first-order transition.
authors: Department of Electrical Engineering, Princeton University, Princeton, New Jersey 08544, USA.
authors: Yang
authors: Y
authors: Liu
authors: D
authors: D
authors: Kamburov
authors: M
authors: M
authors: Shayegan
authors: L N
authors: LN
authors: Pfeiffer
authors: K W
authors: KW
authors: West
authors: K W
authors: KW
authors: Baldwin