“Fuse Safety Device” on an Atomic Scale

We study a nonlinear response of the underdamped generalized Frenkel-Kontorova model (a system of interacting atoms placed into an external periodic potential) on the dc driving force. Both studied variants of the model, one with a transverse degree of freedom, and another with two-dimensional isotropic substrate potential, exhibit an interesting ‘fuse’-like behavior: at small forces the system is in the regime of running kinks with a nonzero conductivity, while at higher forces the system is trapped in an immobile state. This behavior is explained in terms of a dynamical transition between two states of kinks.