title: Metal oxide resistive switching: evolution of the density of states across the metal-insulator transition.
abstract: We report the study of gold-SrTiO3 (STO)-gold memristors where the doping concentration in STO can be fine-tuned through electric field migration of oxygen vacancies. In this tunnel junction device, the evolution of the density of states (DOS) can be followed continuously across the metal-insulator transition (MIT). At very low dopant concentration, the junction displays characteristic signatures of discrete dopant levels. As the dopant concentration increases, the semiconductor band gap fills in but a soft Coulomb gap remains. At even higher doping, a transition to a metallic state occurs where the DOS at the Fermi level becomes finite and Altshuler-Aronov corrections to the DOS are observed. At the critical point of the MIT, the DOS scales linearly with energy N(ϵ)∼ϵ, the possible signature of multifractality.
authors.affiliation: Laboratoire de Physique et d'Etude des Matériaux, UMR 8213, ESPCI-ParisTech-CNRS-UPMC, 10 rue Vauquelin, 75231 Paris, France.
authors.forename: A
authors.initials: A
authors.lastname: Mottaghizadeh
authors.affiliation: Laboratoire de Physique et d'Etude des Matériaux, UMR 8213, ESPCI-ParisTech-CNRS-UPMC, 10 rue Vauquelin, 75231 Paris, France.
authors.forename: Q
authors.initials: Q
authors.lastname: Yu
authors.affiliation: Laboratoire de Physique et d'Etude des Matériaux, UMR 8213, ESPCI-ParisTech-CNRS-UPMC, 10 rue Vauquelin, 75231 Paris, France.
authors.forename: P L
authors.initials: PL
authors.lastname: Lang
authors.affiliation: Laboratoire de Physique et d'Etude des Matériaux, UMR 8213, ESPCI-ParisTech-CNRS-UPMC, 10 rue Vauquelin, 75231 Paris, France.
authors.forename: A
authors.initials: A
authors.lastname: Zimmers
authors.affiliation: Laboratoire de Physique et d'Etude des Matériaux, UMR 8213, ESPCI-ParisTech-CNRS-UPMC, 10 rue Vauquelin, 75231 Paris, France.
authors.forename: H
authors.initials: H
authors.lastname: Aubin