Investigations of stochastic resonance in two-terminal device with vanadium dioxide film

The results of stochastic resonance investigation in a nonlinear system, consisting of a microstructure with a polycrystalline vanadium dioxide (VO2) film grown on sapphire and resistor in series are reported. Nonlinearity of the system was provided due to insulator-metal phase transition in VO2. In the stochastic resonance regime at 100 Hz signal frequency, the transition coefficient of signal-to-noise ratio reached 87 in contrast to 250 for microstructures with VO2 films grown on silica in our previous investigations. The measured characteristics of microstructures with VO2 films grown on silica and sapphire substrates were found to be qualitatively similar. For both substrates, a stochastic resonance was observed at threshold switching voltage from insulating to metallic state of VO2. For sapphire substrate the output signal-to-noise ratio rose at higher signal frequencies. The stochastic resonance phenomenon in VO2 films is explained in terms of the monostable damped oscillator model.