title: Saturation of the anomalous Hall effect in critically disordered ultrathin CNi3 films.
abstract: We demonstrate that a distinct high-disorder anomalous Hall effect phase emerges at the correlated insulator threshold of ultrathin, amorphous, ferromagnetic CNi3 films. In the weak-localization regime, where the sheet conductance G>>e{2}/h, the anomalous Hall resistance of the films increases with increasing disorder and the Hall conductance scales as G{xy} proportional to G{phi} with phi=1.6. However, at sufficiently high disorder the system begins to enter the 2D correlated insulator regime, at which point the Hall resistance R{xy} abruptly saturates and the scaling exponent becomes phi=2. Tunneling measurements show that the saturation behavior is commensurate with the emergence of the 2D Coulomb gap, suggesting that e-e interactions mediate the high-disorder phase.
authors.affiliation: Department of Physics and Astronomy, Louisiana State University, Baton Rouge, Louisiana 70803-4001, USA.
authors.forename: Y M
authors.initials: YM
authors.lastname: Xiong
authors.forename: P W
authors.initials: PW
authors.lastname: Adams
authors.forename: G
authors.initials: G
authors.lastname: Catelani