Soliton structures in a molecular chain model with saturation

TL;DR

This paper models intra-molecular excitations in protein-like chains using a nonlinear Schrödinger equation with saturation, revealing various soliton solutions and their velocity limits, which could impact understanding of molecular dynamics.

Contribution

It introduces a one-dimensional lattice model describing intra-molecular excitations with soliton solutions, including bell solitons, bubbles, kinks, and crowdons, in a saturated nonlinear Schrödinger framework.

Findings

Identifies soliton solutions in a molecular chain model.

Shows the limiting velocity of solitons equals the sound velocity.

Suggests bubble condensation may lead to phase changes.

Abstract

In the present work, we study, by means of a one-dimensional lattice model, the collective excitations corresponding to intra molecular ones of a chain like proteins. It is shown that such excitations are described by the Nonlinear Schrodinger equation with saturation. The solutions obtained here are the bell solitons, bubbles, kinks and crowdons. Since they belong to different sectors on the parametric space, the bubble condensation could give place to some important changes of face in this kind of nonlinear system. Additionally, it is shown that the limiting velocity of the solitons is the velocity of sound waves corresponding to longitudinal vibrations of molecules.