Unconventional computing with diffusive memristors

Diffusive memristors with Ag active metal species are volatile threshold switches featuring spontaneous rupture of conduction channels at small electrical bias. The unique temporal dynamics of the conductance evolution originates from the underlying electrochemical and diffusive dynamics of the active metals in dielectrics, which can be explored for a variety of novel applications in unconventional computing. The superior I-V nonlinearity enables large crossbar arrays for high density non-volatile memories. The relaxation dynamics and the delay dynamics of the conductance evolution lead to faithful synaptic emulators and single-device threshold logic neurons, respectively. Unsupervised learning has been demonstrated with a fully memristive neural network consisting of these artificial synapses and neurons for the first time. In addition, the intrinsic stochasticity of the delay mechanism has been used to realize a true random number generators for security solutions.