Instability of one-dimensional Lennard-Jones system - Particle density dependence

摘要

We report dynamical instability of one-dimensional system with the nearest-neighbor Lennard-Jones interaction. A presence of new certain region between weakly and strongly chaotic region has been found in energy dependence of the maximal Lyapunov exponent. It is numerically shown that the presence of the region is enhanced by decrease of the particle density. The characteristics of the Lennard-Jones system, which are different from the FPU and soft-core system, are explained by means of a local instability of the potential surface. In addition, the relation between the presence of the new region and spatio-temporal pattern is also discussed in the low density cases. [References: 24]