Complex network dynamics in self-assembled atomic-switch networks: prospects for neuromorphic computation

Atomic Scale Dynamics Drive Brain-like Avalanches in Percolating Nanostructured Networks

“…Our percolating devices are fabricated by simple nanoparticle deposition processes. 25,26,49 7 nm Sn nanoparticles are deposited between gold electrodes (spacing 100 µm) on a silicon nitride surface and coalesce to form particles of 20 nm diameter. Deposition is terminated at the onset of conduction, which corresponds to the percolation threshold.…”

“…36,49 The deposition takes place in a controlled environment with a well-defined partial pressure of air and humidity, as described in Ref. 26. This process leads to controlled coalescence and fabrication of robust structures which function for many months, but which yet allow atomic scale switching processes to take place unhindered.…”

“…19,20 This approach was initially driven by investigations of networks of silver nanowires, 12,21 which exhibit interesting dynamics and were used in first attempts to perform waveform regression tasks. 22 More recently other nanowire systems have been investigated 23,24 and it has emerged that percolating-tunneling networks of nanoparticles also exhibit complex dynamics, [25][26][27][28] brain-like avalanches and criticality, 29 and long-range temporal correlations (LRTCs) due to their intrinsically scale-free network architectures. 30 In this Letter we show that brain-like network dynamics in percolating networks of nanoparticles emerge from atomic scale dynamics inside tunnel junctions within the networks.…”

“…Our percolating networks of nanoparticles are formed through deposition of nanoparti-cles onto silicon nitride substrates. 25,26 Deposition is terminated when the fraction (p) of the surface area covered with conducting particles approaches the percolation threshold (p c ∼ 68%), which is a critical value separating the insulating and the conducting states. 36 Fig-…”

Reservoir computing using networks of memristors: effects of topology and heterogeneity

“…1) deposited onto an atomically smooth insulating substrate (the experimental system is described in detail in ref. 15 and 34). Numerical simulations have been used previously to show that the experimental networks of nanoparticles are well described by continuum percolation models.…”