Study of Synaptic Behavior in Doped Transition Metal Oxide-Based Reconfigurable Devices

We report the synaptic characteristics of novel two-terminal reconfigurable devices fabricated using a doped transition metal oxide. These devices demonstrate short-term plasticity, frequency-dependent synaptic augmentation, long-term potentiation, and long-term depression, and have a potential to show spike timing-dependent plasticity that are macroscopically similar to a biological synapse. The underlying mechanism behind the observed synaptic characteristics was studied using charge transport characterization. Based on this study, a fundamental correlation between the governing device physics and the synaptic characteristic has been established. We believe that by carefully engineering the dopants, the synaptic transmission of these devices can be modulated, which will provide a viable route to replicate the functional diversity of a biological neural system on chip.