title: Electron spin polarization by isospin ordering in correlated two-layer quantum Hall systems.
abstract: Enhancement of the electron spin polarization in a correlated two-layer, two-dimensional electron system at a total Landau level filling factor of 1 is reported. Using resistively detected nuclear magnetic resonance, we demonstrate that the electron spin polarization of two closely spaced two-dimensional electron systems becomes maximized when interlayer Coulomb correlations establish spontaneous isospin ferromagnetic order. This correlation-driven polarization dominates over the spin polarizations of competing single-layer fractional quantum Hall states under electron density imbalances.
authors.affiliation: Solid State Physics Laboratory, ETH Zurich, 8093 Zurich, Switzerland.
authors.forename: L
authors.initials: L
authors.lastname: Tiemann
authors.affiliation: Solid State Physics Laboratory, ETH Zurich, 8093 Zurich, Switzerland.
authors.forename: W
authors.initials: W
authors.lastname: Wegscheider
authors.affiliation: Max-Planck-Institute for Solid State Research, Heisenbergstraße 1, 70569 Stuttgart, Germany.
authors.forename: M
authors.initials: M
authors.lastname: Hauser