1/f Noise and Long-term Correlations in Multi-Species Resistor Networks

The 1/f^alpha resistance noise of a thin-film resistor is studied in the temperature range 300-800 K by using a multi-species network model. At low temperatures, resistance fluctuations display long-term correlations expressed by a power-law behavior of the corresponding auto-correlation function. By contrast, at high temperatures resistance fluctuations exhibit a finite and progressively shorter correlation time associated with an exponential cut-off of the auto-correlation function and by alpha < 1. The model predictions are in qualitative agreement with experiments.