title: Nonconventional odd-denominator fractional quantum Hall states in the second Landau level.
abstract: We report the observation of a new fractional quantum Hall state in the second Landau level of a two-dimensional electron gas at the Landau level filling factor ν=2+6/13. We find that the model of noninteracting composite fermions can explain the magnitude of gaps of the prominent 2+1/3 and 2+2/3 states. The same model fails, however, to account for the gaps of the 2+2/5 and the newly observed 2+6/13 states suggesting that these two states are of exotic origin.
authors.affiliation: Department of Physics, Purdue University, West Lafayette, Indiana 47907, USA.
authors.forename: A
authors.initials: A
authors.lastname: Kumar
authors.forename: G A
authors.initials: GA
authors.lastname: Csáthy
authors.forename: M J
authors.initials: MJ
authors.lastname: Manfra
authors.forename: L N
authors.initials: LN
authors.lastname: Pfeiffer
authors.forename: K W
authors.initials: KW
authors.lastname: West