A general method to describe forgetting effect of memristors

Abstract

Building suitable memristor models is essential when memristors are attractive to researchers and play a vital role in fields such as neuromorphic computing. The forgetting effect, which is usually used to mimic forgetting process of biological synapses, should be considered during the modeling process. Several models have been proposed to describe forgetting effect. However, they have some deficiencies in describing forgetting effect, such as boundary problems. In this paper, a general method is presented to resolve these problems. The method is suitable for models that employ an inner state to describe the change of resistance and use a window function to constrain the inner state (e.g., Chang's model, Chen's model, and Berdan's model). When the reason of forgetting effect is considered as dopant diffusion in previous models, the method determines the value of window function and the change rate of inner state according to the integrated result of dopant drift and dopant diffusion. Simulation results indicate that the issues of previous models are solved when the proposed method is applied in these models.