title: A single nanoscale junction with programmable multilevel memory.
abstract: Nanoscale devices that are sensitive to measurement history enable memory applications, and memristors are currently under intense investigation for robustness and functionality. Here we describe the fabrication and performance of a memristor-like device that comprises a single TiO2 nanowire in contact with Au electrodes, demonstrating both high sensitivity to electrical stimuli and high levels of control. Through an electroforming process, a population of charged dopants is created at the interface between the wire and electrode that can be manipulated to demonstrate a range of device and memristor characteristics. In contrast to conventional two-terminal memristors, our device is essentially a diode that exhibits memristance in the forward bias direction. The device is easily reset to the off state by a single voltage pulse and can be incremented to provide a range of controllable conductance states in the forward direction. Electrochemical modification of the Schottky barrier at the electrodes is proposed as an underlying mechanism, and six-level memory operations are demonstrated on a single nanowire.
authors.affiliation: School of Chemistry and CRANN Institute, Trinity College Dublin , Dublin 2, Ireland.
authors.forename: Curtis
authors.initials: C
authors.lastname: O'Kelly
authors.forename: Jessamyn A
authors.initials: JA
authors.lastname: Fairfield
authors.forename: John J
authors.initials: JJ
authors.lastname: Boland
keywords: TiO2; engineered vacancies; memristor; multilevel memory; multistate memory; single nanowire