Activation-tunneling dynamics of extended systems in periodic potential relief

The dynamics of systems in barrier structures is determined by the rate of fluctuation decay of metastable states in intermediate minima of the potential relief. When the temperature decreases, thermal fluctuations freeze out and are replaced by quantum ones, which leads to a kind of phase transition in the dynamics. The nature of this transition in various systems is analogous to either the second or first kind of transition. The transition temperature depends on the degree of metastability, and can be controlled by an external load. The purpose of this work is to calculate this dependence for an extended system in a tilted periodic relief of the “washboard” type in a wide range of load changes.