Electrolyte Gated Synaptic Transistor based on an Ultra-Thin Film of La0.7Sr0.3MnO3

Developing electronic devices capable of reproducing synaptic functionality is essential in the context of implementing fast, low-energy consumption neuromorphic computing systems. Hybrid ionic/electronic three-terminal synaptic transistors are promising as efficient artificial synapses since they can process information and learn simultaneously. In this work, an electrolyte-gated synaptic transistor is reported based on an ultra-thin epitaxial La0.7Sr0.3MnO3 (LSMO) film, a half-metallic system close to a metal-insulator transition. The dynamic control of oxygen composition of the manganite ultra-thin film with voltage pulses applied through the gate terminal allows reversible modulation of its electronic properties in a non-volatile manner. The conductance modulation can be finely tuned with the amplitude, duration, and number of gating pulses, providing different alternatives to gradually update the synaptic weights. The transistor implements essential synaptic features such as excitatory postsynaptic potential, paired-pulse facilitation, long-term potentiation/depression of synaptic weights, and spike-time-dependent plasticity. These results constitute an important step toward the development of neuromorphic computing devices leveraging the tunable electronic properties of correlated oxides, and pave the way toward enhancing future device functionalities by exploiting the magnetic (spin) degree of freedom of the half metallic transistor channel.