Dimensional Crossover by a Local Inhomogeneity
in Soliton-Pair Nucleation

Abstract

Soliton-pair nucleation rates Γ = A exp(-B) are studied in highly biased sine-Gordon systems with a local inhomogeneity for both a thermal activation regime and a quantum tunneling regime. It is found that the local inhomogeneity strongly affects the nucleation rates by modifying the bias-dependence of the exponent B. This change in the exponent B is explained by a dimensional crossover caused by the local inhomogeneity. The necessary condition for observation of inhomogeneity effects is also discussed.