Dynamics of Soliton-Like Excitations in a Chain of a Polymer Crystal: Influence of Neighbouring Chains Mobility

Abstract

We investigate influence of mobility of neighbouring chains on dynamics of soliton-like excitations in a chain of the simplest polymer crystal (polyethylene in the "united atoms" approximation) using molecular dynamics simulation. We present results for point-like structural defects: static and moving at low, medium and high velocities; and examine how the structure of a crystal will affect them.

Fast soliton-like charge pulses in insulating polymers

“…Under these circumstances the pulse moves too fast to allow any independent transport of its individual charges with the speed of sound forming an upper bound to its velocity, which is not reached in these experiments. Such a moving coherent entity is by definition a solitary wave, 35,45,46 i.e., the pulse is a charged soliton. 34 However, the amount of charge in the pulse will be determined by the need for it to produce a field large enough to produce the compression that will allow its advance as a coherent entity, rather than the single electron soliton of Bylander et al 34 Table V shows that pulse charge/ area depends on the insulating polymer (INS1 or INS2).…”

Aspects of sine-Gordon solitons, defects and gates

“…In this letter it is intended to expand upon this observation and point out a possible use. Naturally, it must be said at the outset that this work is entirely theoretical and speculative since, although it appears to be the case that sine-Gordon or other solitons can appear within special systems, for example Josephson junctions, polymers, or liquid crystals (see for example [3,4,5] and references therein), it is not yet known how the specific defect introduced and described mathematically in [1] might be realised in an a genuine physical system.…”

A pseudo‐spectral method that uses an overlapping multidomain technique for the numerical solution of sine‐Gordon equation in one and two spatial dimensions

“…The SG equation is known to be a canonical model for a wide variety of physical systems such as propagation of ultra‐short optical pulses in resonant laser media , a unitary theory of elementary particles , propagation of magnetic flux in Josephson junctions , motion of dislocations in crystals , DNA dynamics , and many others . In the following section, we explain some of these applications.…”

“…Considering the topological solitons of SG type, a vacancy without breaking of covalent bonds can move along the chain with a subsonic velocity, maintaining its localization and without disrupting the crystal structure outside the region of the defect. This means that at velocities not too close to speed of sound, the vacancy dynamics should be as a soliton .…”