Abstract
We report the first experimental study of the energy gap for the fractional quantum Hall states at Landau-level filling factors ν=1/3 and 2/3 in a variable-width electron system realized in a selectively doped, parabolic, AlGaAs quantum well. We observe a dramatic decrease in the measured energy gaps as the electron-layer thickness increases and the electric-subband separation decreases, which we interpret as the collapse of the correlated fractional states.
- Received 18 July 1990
DOI:https://doi.org/10.1103/PhysRevLett.65.2916
©1990 American Physical Society