Switching dynamics of oxygen-vacancy memristors based on cuprate superconductors

Abstract

Resistive switching phenomena have attracted increased attention over the years because of their technological relevance, particularly for applications like nonvolatile memories and memristors, which are of much interest for emerging neuromorphic computation schemes. Devices based on complex oxides are especially appealing, since these materials present a plethora of functionalities (magnetism, superconductivity, photoconductivity…) and resistive switching mechanisms. Determining their characteristic timescales is crucial, both for fundamental understanding and regarding the potential applications. Here, we analyze the resistive switching dynamics of tunnel junctions between a cuprate superconductor and a metallic counter-electrode, in which memristive behavior stems from an electrochemical redox reaction across their interface. We compare these junctions with similar ones in which a thin oxide ferroelectric layer is placed in between both electrodes, expected to promote faster ferroelectric switching effects. We find that all the junctions show similar dynamics, pointing to oxygen ion exchange as the dominant mechanism in all cases. Interestingly, very strong resistance switching effects are observed down to the 100 ns timescale, thus allowing for applications where fast switching is required, even at cryogenic temperatures at which superconducting effects can be exploited.