Analog and digital Reset processes observed in Pt/CuO/Pt memristive devices

The digital resistive switching with abrupt state change is suitable for the applications of information storage and logical operation, while the analog resistive switching with gradual state change is required in the neuromorphic computing system. This paper reports the Set voltage polarity dependent analog and digital Reset processes coexisted in Pt/CuO/Pt memristive devices. After a negative Set process, the device exhibited a digital Reset process when applying negative bias. In contrast, an analog Reset process could be achieved, following a positive Set process. These digital and analog Reset processes can convert to each other by controlling the Set bias polarity. It is proposed that the Joule-heating effect induced filament rupture is responsible for the digital Reset process, while the analog Reset process can be attributed to the filament rupture dominated by the ion migration under the external electric field.