Controllability of Relaxation Behavior in Ag-based Diffusive Memristors.

Diffusive memristors - based on the formation and rupture of Ag or Cu metallic filaments within a switching matrix - display a variety of interesting features such as thresholding, self-relaxation, and tunable characteristics of the switching times that can be exploited for applications in emerging memory and neuromorphic computing (NC) areas [1]–[2]. For example, the modulation of the switching times, especially the relaxation time ( $t_{\mathrm{r}}$ ) makes diffusive memristors a good fit as a simple and scalable circuit element for temporal- and/or rate-based coding in emerging computing [3]. Despite this potential, a reliable means to modulate $t_{\mathrm{r}}$ has yet to be found. Here we show a way to control $t_{\mathrm{r}}$ by employing series resistors in combination with different programming schemes. Additionally, we show a decay of $t_{\mathrm{r}}$ as a function of programming voltage ( $V_{\mathrm{p}}$ ) as opposed to previous observations of rising $t_{\mathrm{r}}$ with increasing $V_{\mathrm{p}}$ .