Complexity of Shapiro steps.

We demonstrate on the example of dc+ac driven overdamped Frenkel-Kontorova model that an easily calculable measure of complexity can be used for the examination of Shapiro steps in the presence of noise. In real systems, noise causes melting or even disappearance of Shapiro steps, which makes their analysis in the usual way from the response function very difficult. Unlike in the conventional approach, here, by calculating Kolmogorov complexity of the certain area in the response function we were able to detect Shapiro steps, measure their size with desired precision and examine their temperature dependence. The aim of this work is to provide scientists, particularly experimentalists, an unconventional but very practical and easy tool for examination of Shapiro steps in real systems.