Spatial Interactions in Hydrogenated Perovskite Nickelate Synaptic Networks

A key aspect of how the brain learns and enables decision-makingprocesses is through synaptic interactions. Electrical transmissionand communication in a network of synapses are modulated by extracellularfields generated by ionic chemical gradients. Emulating such spatialinteractions in synthetic networks can be of potential use for neuromorphiclearning and the hardware implementation of artificial intelligence.Here, we demonstrate that in a network of hydrogen-doped perovskitenickelate devices, electric bias across a single junction can tunethe coupling strength between the neighboring cells. Electrical transportmeasurements and spatially resolved diffraction and nanoprobe X-rayand scanning microwave impedance spectroscopic studies suggest thatgraded proton distribution in the inhomogeneous medium of hydrogen-dopednickelate film enables this behavior. We further demonstrate signalintegration through the coupling of various junctions.