A Three-Terminal Memristive Artificial Neuron with Tunable Firing Probability

The human brain facilitates information processing via generating and receiving temporal patterns of short voltage pulses, a.k.a. neural spikes. This approach simultaneously grants low-power operation as well as a high degree of noise immunity and fault tolerance at a small footprint and simplistic structure of the neurons. To date, the latter two key features are critically missing from the toolbox of artificial spiking neural network hardware, hindering the development of scalable and sustainable artificial intelligence (AI) platforms. Here, a compact, gate-tunable neuron circuit is demonstrated, and its potential as a functional leaky integrate-and-fire (LIF) neuron is explored. It relies on a single nanoscale three-terminal (3T) memristor device, which has been downscaled by 30% compared to previous work, where the set voltage and, thereby, the spiking probability of the neuron circuit can be widely tuned by the low-voltage operation of the gate electrode. The influence of the gate voltage on the two-terminal (2T) current-voltage characteristics is measured, statistically analyzed, and further utilized in a custom-built LTspice model. The circuit simulations account for the experimentally observed, adjustable set voltage. The presented results demonstrate the merits of 3T memristors as compact, tunable, and versatile artificial neurons for neuromorphic computing applications.