Dynamics of Solitary Waves Induced by Shock Impulses in a Linear Atomic Chain.

摘要

The propagation of nonlinear waves induced by a shock impulse in a linear atomic chain of finite but large length is investigated numerically with a model interatomic potential. The shock impulse is initiated by giving the first atom in the chain an initial velocity vi toward its neighbor. We find that there exists a velocity such that a solution is produced by this impulse with a constant energy and supersonic velocity. Studies of the motion of the atom during the passage of this soliton reveal a behavior similar to that expected from the collision of hard spheres. However the induced pulse propagates below the speed of sound and gradually disperses through the emission of phonons. Finally, in agreement with earlier studies using other model potentials, we find that a soliton can be generated with sufficient energy to spall an atom from the end of the chain.