A synapse memristor model with forgetting effect

•We improved the ion diffusion term proposed in literature [9].•We redesigned the previous model as a dynamical model with three variables.•The new model can capture the new finding forgetting behavior in memristor.•The new model can define the transition from short term memory to long term memory.•The new model is better matched with the physical memristor (Pd/WOx/W).

In this Letter we improved the ion diffusion term proposed in literature [13] and redesigned the previous model as a dynamical model with two more internal state variables ‘forgetting rate’ and ‘retention’ besides the original variable ‘conductance’. The new model can not only describe the basic memory ability of memristor but also be able to capture the new finding forgetting behavior in memristor. And different from the previous model, the transition from short term memory to long term memory is also defined by the new model. Besides, the new model is better matched with the physical memristor (Pd/WOx/W) than the previous one.