The dynamics of a one-dimensional harmonic chain in the presence of a strong, incommensurate, sinusoidal potential and a uniform force F is investigated numerically. A threshold force $F_T$ exists above which steady-state motion occurs. Near threshold, the linear and nonlinear responses of the system exhibit nontrivial critical behavior. Critical exponents describing the transition to a moving state are calculated, and scaling relations between them are conjectured.

• Received 25 May 1988

DOI:https://doi.org/10.1103/PhysRevA.38.6338