Breathers in a model of a polymer with secondary structure

A simple model of a polymer is considered: a chain of (different) point masses, connected by harmonic springs, embedded in two dimensional space. In order to determine conditions for existence and stability of breather excitations, the method of numerical continuation of a breather solution from the anticontinuous limit is employed. Approaching the limit of equal masses, stable breather solutions are found only within an extremely narrow band of frequencies.