title: Insulating and fractional quantum hall states in the first excited Landau level.
abstract: The observation of new insulating phases of two-dimensional electrons in the first excited Landau level is reported. These states, which are manifested as reentrant integer quantized Hall effects, exist alongside well-developed even-denominator fractional quantized Hall states at nu = 7/2 and 5/2 and new odd-denominator states at nu = 3+1/5 and 3+4/5.
authors.affiliation: California Institute of Technology, Pasadena, California 91125, USA.
authors.forename: J P
authors.initials: JP
authors.lastname: Eisenstein
authors.forename: K B
authors.initials: KB
authors.lastname: Cooper
authors.forename: L N
authors.initials: LN
authors.lastname: Pfeiffer
authors.forename: K W
authors.initials: KW
authors.lastname: West