title: Characterizing neutral modes of fractional states in the second Landau level.
abstract: Fractionally charged quasiparticles, which obey non-abelian statistics, were predicted to exist in the ν=8/3, ν=5/2, and ν=7/3 fractional quantum Hall states (in the second Landau level). Here we present measurements of charge and neutral modes in these states. For both ν=7/3 and ν=8/3 states, we found a quasiparticle charge e=1/3 and an upstream neutral mode only in ν=8/3-excluding the possibility of non-abelian Read-Rezayi states and supporting Laughlin-like states. The absence of an upstream neutral mode in the ν=7/3 state also proves that edge reconstruction was not present in the ν=7/3 state, suggesting its absence also in ν=5/2 state, and thus may provide further support for the non-abelian anti-pfaffian nature of the ν=5/2 state.
authors.affiliation: Braun Center for Submicron Research, Department of Condensed Matter Physics, Weizmann Institute of Science, Rehovot 76100, Israel.
authors.forename: M
authors.initials: M
authors.lastname: Dolev
authors.forename: Y
authors.initials: Y
authors.lastname: Gross
authors.forename: R
authors.initials: R
authors.lastname: Sabo
authors.forename: I
authors.initials: I
authors.lastname: Gurman
authors.forename: M
authors.initials: M
authors.lastname: Heiblum
authors.forename: V
authors.initials: V
authors.lastname: Umansky
authors.forename: D
authors.initials: D
authors.lastname: Mahalu