Synaptic Modulation of Conductivity and Magnetism in a CoPt‐Based Electrochemical Transistor

Abstract

Among various types of neuromorphic devices toward artificial intelligence, the electrochemical synaptic transistor emerges, in which the channel conductance is modulated by the insertion of ions according to the history of gate voltage across the electrolyte. Despite the striking progress in exploring novel channel materials, few studies report on the ferromagnetic metal‐based synaptic transistors, limiting the development of spin‐based neuromorphic devices. Herein, synaptic modulation of both conductivity and magnetism based on an electrochemical transistor with a metallic channel of ferromagnetic CoPt alloy is presented. Its essential synaptic functionalities in the transistor are demonstrated, including depression and potentiation of synaptic weight and paired‐pulse facilitation (PPF). Then, short‐to‐long‐term plasticity transition induced by different gate parameters, such as amplitude, duration, and frequency, is shown. Furthermore, the device presents multilevel and reversible nonvolatile states in both conductivity and coercivity. The results demonstrate simultaneous modulation of conductivity and magnetism, paving the way for building future spin‐based multifunctional synaptic devices.