Abstract
Abstract
The diatomic linear chain with nearest-neighbor spring constants C
1 and C
2 has topologically different bulk states for C
1 ≷ C
2. A finite chain of N unit cells and fixed ends (the first and last spring is C
1) exhibits two topological end states within the gap for C
1 > C
2. We investigate the effect of an impedance mismatch by varying the first and last ‘boundary’ spring constant termed C
F from its ideal value C
1. C
F = 0 represents an open end and does never lead to topological states. C
F → ∞ means that also the next site to the boundary is fixed, leading to topological states only for C
1 < C
2 since now the first movable spring is C
2. Within a range of C
F around C
1 topological end states are preserved for C
1 > C
2. For C
2 > C
1, topological end states occur when C
F exceeds a certain value.
Subject
General Physics and Astronomy