Synaptic modulation of conductivity and magnetism in a CoPt-based electrochemical transistor

TL;DR

This paper demonstrates a ferromagnetic CoPt-based electrochemical transistor that modulates both electrical conductivity and magnetism, enabling multifunctional spin-based neuromorphic devices with synaptic-like behaviors.

Contribution

It introduces a novel ferromagnetic metal-based synaptic transistor capable of simultaneously modulating conductivity and magnetism, advancing spin-based neuromorphic technology.

Findings

Demonstrated synaptic functionalities including depression and potentiation.

Achieved transition from short- to long-term plasticity with gate parameters.

Realized multilevel, reversible nonvolatile states in conductivity and coercivity.

Abstract

Among various types of neuromorphic devices towards 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. Here, we present synaptic modulation of both conductivity as well as magnetism based on an electrochemical transistor with a metallic channel of ferromagnetic CoPt alloy. We first demonstrate its essential synaptic functionalities in the transistor, including depression and potentiation of synaptic weight, and paired-pulse facilitation. Then, we show a short- to long-term plasticity transition induced by different gate parameters, such as amplitude, duration, and frequency. 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.