Ndr Effects in a Locally-Active Memristor Induce Small-Signal Amplification in a Simple Cell

The Pt/NbOx/Nb2O5/Pt threshold switch, manufactured at NaMLab, may admit a negative differential resistance (NDR). For example, this occurs when a constant voltage, let fall across a two-element one-port, composed of its series connection with a suitable linear resistor, stabilizes its bias point on a branch of the respective DC current-voltage characteristic, along which the slope assumes negative values. Around a bias point of this kind, the device may act as a source of local energy, justifying the locally-active attribute it is conferred. In past research studies the capability of the nanodevice to generate infinitesimal energy around a NDR bias point was exploited to induce the emergence of dramatic local phenomena in otherwise-dumb circuits, including the Hopf Supercritical and Pitchfork Bifurcations, which, while destabilizing a quiescent steady state, respectively spawn sine-wave-alike oscillations, or two new stable quiescent points, concurrently. In this research study, the local energy, which the switch releases about the NDR bias point, when a small-signal sine wave signal, superimposed on top of the DC stimulus, is applied across the two-element one-port, is leveraged to induce the development of larger oscillations across the resistor than those generated by the input source. While the key findings of our numerical investigations are provided here, the underlying theoretical analysis, supported by experimental verification, shall be reported in a Journal paper.