Soliton density in the chaotic phase and the Devil's staircase

Abstract

The behaviour of the soliton density is examined, in the chaotic phase of some incommensurate systems. According to many authors, in this region, very close to the Lock-in transition where the Landau approximation is not valid, a devil's staircase exists . In this letter we try to explain the critical behaviour of the soliton density in the above region with the help of the fractal structure of the devil's staircase. Comparison between theory and experimental data favours this model.