title: Detection of a Landau band-coupling-induced rearrangement of the Hofstadter butterfly.
abstract: The spectrum of 2D electrons subjected to a weak 2D potential and a perpendicular magnetic field is composed of Landau bands with a fractal internal pattern of subbands and minigaps referred to as Hofstadter's butterfly. The Hall conductance may serve as a spectroscopic tool as each filled subband contributes a specific quantized value. Advances in sample fabrication now finally offer access to the regime away from the limiting case of a very weak potential. Complex behavior of the Hall conductance is observed and assigned to Landau band-coupling-induced rearrangements within the butterfly.
authors.affiliation: Max-Planck-Institut für Festkörperforschung, D-70569 Stuttgart, Germany.
authors.forename: M C
authors.initials: MC
authors.lastname: Geisler
authors.forename: J H
authors.initials: JH
authors.lastname: Smet
authors.forename: V
authors.initials: V
authors.lastname: Umansky
authors.forename: K
authors.initials: K
authors.lastname: von Klitzing
authors.forename: B
authors.initials: B
authors.lastname: Naundorf
authors.forename: R
authors.initials: R
authors.lastname: Ketzmerick
authors.forename: H
authors.initials: H
authors.lastname: Schweizer