Spatiotemporal Summation of a Triple-Terminal Light-Induced Artificial Synapse

In the biological nervous system, repetitive-pulse signals from different presynaptic neurons may correlate to produce a specific association at the postsynaptic neuron for complex neural encoding. Here, the fabrication and characterization of a triple-emitter light-induced synaptic device artificial synapse is proposed to mimic excitatory postsynaptic voltage (EPSV) summation of the biological nervous system. When repetitive-pulse signals with different periods are synchronously applied to three presynaptic terminals, temporal, and spatial EPSV summations lead to synaptic strengthening. Resonant spatiotemporal correlations occur because the continuous activities make the presynaptic inputs correlate with respect to each other. Experimental results demonstrate three different resonant EPSV correlations generated by a combination of each of the two repetitive-pulse signals, which agree well with the simulations based on the convolution operation and the nonlinear distortion function. These results suggest that the multiple-emitter light-induced artificial synapse is promising for the emulation of biological neural networks.