Lévy noise-induced phenomena in CO oxidation on Ir(111) surfaces.

The influences of external Lévy noise in CO oxidation on the Ir(111) surfaces are numerically examined. Depending on the control parameters, such as the temperature T  and the CO fraction Y  in the total reactant input gas flux, the reaction exhibits one or two stable stationary states in the absence of noise. Lévy noise is introduced in the reaction by randomly varying the quality of the influx mixture. We then observe a large variety of different types of behaviors depending on the initial CO fraction Y, in particular, the phenomenon of noise-induced shifts of the steady state in the monostable regime is regarded. We also show how the stationary probability density changes in terms of stochastic bifurcation when Lévy noise is applied in the bistable regime. The results provide a strong evidence for noise-induced transitions. We concentrate on the effects of the stability index α, the skewness parameter β,  and the noise intensity D  that emphasize the differences with Gaussian fluctuations.