{SSH coupled-spring systems

TL;DR

This paper investigates the topological properties of SSH coupled-spring systems, revealing how boundary conditions and spring force variations influence the existence of edge modes regardless of the bulk phase.

Contribution

It demonstrates that boundary force adjustments can induce edge modes independently of the bulk topological phase and boundary conditions.

Findings

Edge modes can appear regardless of boundary conditions.

Varying boundary spring constants induces edge modes.

Edge modes exist even in trivial bulk phases.

Abstract

It is known that there is also a topological phase in the SSH coupled-spring system with the fixed-end boundary conditions. When this is the case, there would exist edge modes on its boundaries. In contrast, if the system satisfies the free-end boundary conditions, there is no edge mode, even if it is the topological phase. We show that by varying the force constant of the spring by the boundary in such a system, edge modes would generally appear independent of whether the bulk of the system is in the topological or trivial phases. Moreover, edge modes could exist even if the system satisfies the free-end boundary conditions.