Synchronization: The ratchet phenomenon

In this paper some simple models of coupled oscillators are defined. They are used as tools to analyze properties of synchronization domains. It is possible to get the general organization of these domains (generally known as tongues), particularly when the coupling or the forcing signal is “square”. At large forcing a phenomenon, very similar to the ratchet wheel mechanism, takes place and many synchronization domains disappear. Generally the tongue associated with the relative winding number 1/1 becomes predominant and only tongues with relative winding number p/q < 1 remain. This phenomenon is rather general and appears in many real situations. It is related with motion and transport in physical and biological sciences.