title: Direct measurement of the g factor of composite fermions.
abstract: The activation gap Delta of the fractional quantum Hall states at constant fillings nu=2/3 and 2/5 has been measured as a function of the perpendicular magnetic field B. A linear dependence of Delta on B is observed while approaching the spin-polarization transition. This feature allows a direct measurement of the g factor of composite fermions which appears to be heavily renormalized by interactions and strongly sensitive to the electronic filling factor.
authors.affiliation: Institut für Festkörperphysik, Universität Hannover, Germany.
authors.forename: F
authors.initials: F
authors.lastname: Schulze-Wischeler
authors.forename: E
authors.initials: E
authors.lastname: Mariani
authors.forename: F
authors.initials: F
authors.lastname: Hohls
authors.forename: R J
authors.initials: RJ
authors.lastname: Haug