Chaos in dynamic atomic force microscopy.

In tapping mode atomic force microscopy (AFM) the highly nonlinear tip–sampleinteraction gives rise to a complicated dynamics of the microcantilever. Apart from thewell-known bistability under typical imaging conditions the system exhibits acomplex dynamics at small average tip–sample distances, which are typical operationconditions for mechanical dynamic nanomanipulation. In order to investigate thedynamics at small average tip sample gaps experimental time series data are analysedemploying nonlinear analysis tools and spectral analysis. The correlation dimension iscomputed together with a bifurcation diagram. By using statistical correlationmeasures such as the Kullback–Leibler distance, cross-correlation and mutualinformation the dataset can be segmented into different regimes. The analysis revealsperiod-3, period-2 and period-4 behaviour, as well as a weakly chaotic regime. [ABSTRACT FROM AUTHOR]