Question

When calculating the presence of soliton or anti-soliton in the extreme dimerization polyacetylene SSH model, we say that in the case of open-boundary condition and odd number of atoms, we must have an edge soliton. But why is that the case? I understand that we must have a soliton, but why is the edge mode preferred over the bulk case?

Answer 1

The presence of an edge soliton in the extreme dimerization polyacetylene SSH model, when there are open-boundary conditions and an odd number of atoms, is due to the specific boundary conditions and the odd number of atoms in the system.

Step-by-step explanation:

In the extreme dimerization polyacetylene SSH model, when there are open-boundary conditions and an odd number of atoms, an edge soliton is preferred over the bulk case.

This is because the boundary conditions dictate the behavior of the normal modes of the system.

For example, in a one-dimensional system, an edge soliton can be thought of as a localized excitation that exists at the boundary, while a bulk soliton would be spread out within the system.

The presence of an edge soliton is a consequence of the specific boundary conditions and the odd number of atoms in the system.