Sliding charge-density waves in periodic and disordered lattices

Abstract

The Frenkel-Kontorova model (which consists of a chain of atoms connected by springs able to slide in a sinusoidal potential well) is applied to the problem of a charge-density wave moving through a periodic lattice under an applied external electric field. Computer experiments are reported for this model which partially support Lee, Rice, and Anderson's result which states that an incommensurate periodic lattice does not pin a charge-density wave. Experiments for a chain of atoms containing impurities partially support the conjectures made by the present author which state that weak random impurities need not pin a charge-density wave. For impurity strengths actually encountered in real systems, however, the charge-density wave most likely will be pinned.