title: Spin transition in the ν=8/3 fractional quantum Hall effect.
abstract: We present here the results from a density dependent study of the activation energy gaps of the fractional quantum Hall effect states at Landau level fillings ν=8/3 and 7/3 in a series of high quality quantum wells. In the density range from 0.5×10(11) to 3×10(11) cm(-2), the 7/3 energy gap increases monotonically with increasing density, supporting its ground state being spin polarized. For the 8/3 state, however, its energy gap first decreases with increasing density, almost vanishes at n~0.8×10(11) cm(-2), and then turns around and increases with increasing density, clearly demonstrating a spin transition.
authors.affiliation: Sandia National Laboratories, Albuquerque, New Mexico 87185, USA.
authors.forename: W
authors.initials: W
authors.lastname: Pan
authors.forename: K W
authors.initials: KW
authors.lastname: Baldwin
authors.forename: K W
authors.initials: KW
authors.lastname: West
authors.forename: L N
authors.initials: LN
authors.lastname: Pfeiffer
authors.forename: D C
authors.initials: DC
authors.lastname: Tsui