Role of Commensurability Energy in Impurity Pinning of One-Dimensional Charge Density Waves

Abstract

Competition between the impurity pinning and the commensurability pinning is investigated by studying the one-dimensional charge density wave (CDW) systems under the external sinusoidal potential, −B cos θ, where θ is the phase of CDW. The pinning of θ is examined by both numerical and analytical methods which turn out to yield the consistent results. It is shown that both types of pinning coexist for all values of B and that the state pinned by impurities undergoes gradual change into the state pinned by the commensurability potential as B increases.