Collective capacitive and memristive responses in random nanowire networks: Emergence of critical connectivity pathways

Random nanowire networks (NWNs) are promising synthetic architectures for non-volatile memory devices and hardware-based neuromorphic applications due to their history-dependent responses, recurrent connectivity, and neurosynaptic-like behaviors. Such brain-like functions occur due to emergent resistive switching phenomena taking place in the interwire junctions which are viewed as memristive systems; they operate as smart analogue switches whose resistance depends on the history of the input voltage/current. We successfully demonstrated that NWNs made with a particular class of memristive junctions can exhibit a highly-selective conduction mechanism which uses the lowest-energy connectivity path in the network identified as the “winner-takes-all” state. However, these complex networks do not always behave in the same fashion; in the limit of sufficiently low input currents (preceding this selective conduction regime), the system behaves as a leakage capacitive network and its electrical activation is dri...