Metal-Insulator Transition in UltrathinLaNiO3Films

Abstract

Transport in ultrathin films of ${\mathrm{LaNiO}}_3$ evolves from a metallic to a strongly localized character as the film’s thickness is reduced and the sheet resistance reaches a value close to $h/e^2$, the quantum of resistance in two dimensions. In the intermediate regime, quantum corrections to the Drude low-temperature conductivity are observed; they are accurately described by weak localization theory. Remarkably, the negative magnetoresistance in this regime is isotropic, which points to magnetic scattering associated with the proximity of the system to either a spin-glass state or the charge ordered antiferromagnetic state observed in other rare earth nickelates. DOI: http://dx.doi.org/10.1103/PhysRevLett.106.246403 © 2011 American Physical Society