title: Contrasting behavior of the 5/2 and 7/3 fractional quantum Hall effect in a tilted field.
abstract: Using a tilted-field geometry, the effect of an in-plane magnetic field on the even denominator nu=5/2 fractional quantum Hall state is studied. The energy gap of the nu=5/2 state is found to collapse linearly with the in-plane magnetic field above approximately 0.5 T. In contrast, a strong enhancement of the gap is observed for the nu=7/3 state. The radically distinct tilted-field behavior between the two states is discussed in terms of Zeeman and magneto-orbital coupling within the context of the proposed Moore-Read Pfaffian wave function for the 5/2 fractional quantum Hall effect.
authors.affiliation: Department of Physics, McGill University, Montreal, H3A 2T8, Canada.
authors.forename: C R
authors.initials: CR
authors.lastname: Dean
authors.forename: B A
authors.initials: BA
authors.lastname: Piot
authors.forename: P
authors.initials: P
authors.lastname: Hayden
authors.forename: S
authors.initials: S
authors.lastname: Das Sarma
authors.forename: G
authors.initials: G
authors.lastname: Gervais
authors.forename: L N
authors.initials: LN
authors.lastname: Pfeiffer
authors.forename: K W
authors.initials: KW
authors.lastname: West