title: Nonlocal Polarization Feedback in a Fractional Quantum Hall Ferromagnet.
abstract: In a quantum Hall ferromagnet, the spin polarization of the two-dimensional electron system can be dynamically transferred to nuclear spins in its vicinity through the hyperfine interaction. The resulting nuclear field typically acts back locally, modifying the local electronic Zeeman energy. Here we report a nonlocal effect arising from the interplay between nuclear polarization and the spatial structure of electronic domains in a ν=2/3 fractional quantum Hall state. In our experiments, we use a quantum point contact to locally control and probe the domain structure of different spin configurations emerging at the spin phase transition. Feedback between nuclear and electronic degrees of freedom gives rise to memristive behavior, where electronic transport through the quantum point contact depends on the history of current flow. We propose a model for this effect which suggests a novel route to studying edge states in fractional quantum Hall systems and may account for so-far unexplained oscillatory electronic-transport features observed in previous studies.
authors.affiliation: Solid State Physics Laboratory, ETH Zürich, 8093 Zürich, Switzerland.
authors.forename: Szymon
authors.initials: S
authors.lastname: Hennel
authors.affiliation: Solid State Physics Laboratory, ETH Zürich, 8093 Zürich, Switzerland.
authors.forename: Beat A
authors.initials: BA
authors.lastname: Braem
authors.affiliation: Solid State Physics Laboratory, ETH Zürich, 8093 Zürich, Switzerland.
authors.forename: Stephan
authors.initials: S
authors.lastname: Baer
authors.affiliation: Solid State Physics Laboratory, ETH Zürich, 8093 Zürich, Switzerland.
authors.forename: Lars
authors.initials: L
authors.lastname: Tiemann
authors.affiliation: Solid State Physics Laboratory, ETH Zürich, 8093 Zürich, Switzerland.
authors.forename: Pirouz
authors.initials: P
authors.lastname: Sohi
authors.affiliation: Solid State Physics Laboratory, ETH Zürich, 8093 Zürich, Switzerland.
authors.forename: Dominik
authors.initials: D
authors.lastname: Wehrli
authors.affiliation: Solid State Physics Laboratory, ETH Zürich, 8093 Zürich, Switzerland.
authors.forename: Andrea
authors.initials: A
authors.lastname: Hofmann
authors.affiliation: Solid State Physics Laboratory, ETH Zürich, 8093 Zürich, Switzerland.
authors.forename: Christian
authors.initials: C
authors.lastname: Reichl
authors.affiliation: Solid State Physics Laboratory, ETH Zürich, 8093 Zürich, Switzerland.
authors.forename: Werner
authors.initials: W
authors.lastname: Wegscheider
authors.affiliation: Solid State Physics Laboratory, ETH Zürich, 8093 Zürich, Switzerland.
authors.forename: Clemens
authors.initials: C
authors.lastname: Rössler
authors.affiliation: Solid State Physics Laboratory, ETH Zürich, 8093 Zürich, Switzerland.
authors.forename: Thomas
authors.initials: T
authors.lastname: Ihn
authors.affiliation: Solid State Physics Laboratory, ETH Zürich, 8093 Zürich, Switzerland.
authors.forename: Klaus
authors.initials: K
authors.lastname: Ensslin
authors.affiliation: Niels Bohr International Academy and Center for Quantum Devices, Niels Bohr Institute, University of Copenhagen, 2100 Copenhagen, Denmark.
authors.forename: Mark S
authors.initials: MS
authors.lastname: Rudner
authors.affiliation: Institut für Theoretische Physik, Universität Leipzig, D-04009 Leipzig, Germany.
authors.forename: Bernd
authors.initials: B
authors.lastname: Rosenow