Threshold Switching Memristor Based on the BaTiO3/Nb:SrTiO3 Epitaxial Heterojunction for Neuromorphic Computing

A highly repeatable threshold switching was found in the Au/Cr/BaTiO3/Nb:SrTiO3/In system. Based on the dependence of threshold and hold voltage on the compliance current and measurement temperature, threshold switching can be ascribed to the formation/disrupture of oxygen vacancy conductive filaments. Short-term synaptic plasticity of biological synapses has been successfully simulated in this device. Furthermore, the short-term depression was found to be greatly enhanced at a small pulse width/amplitude/interval. The short-term potentiation and depression can be successfully switched using an alternating low- and high-frequency pulse sequence. These results provide insights into the potential for using BaTiO3/Nb:SrTiO3 epitaxial heterojunction in neuromorphic computing.