  We theoretically propose a polymer-based nano-device consisting of a single
trans-polyacetylene (tPA) molecule capacitively coupled to external voltage
gates. We model the integrated device using a Su-Schrieffer-Heeger (SSH)-like
Hamiltonian, and we demonstrate the emergence of localized domain walls (DWs)
with quantized charges (i.e., soliton excitations) localized at the gates.
Interestingly, by increasing the applied voltage, multiple discrete charges can
be accumulated, which may be useful for potential technological applications.
Exploiting the topological character of the solitonic excitations of tPA, this
device can be considered as an organic-based quantum dot with a very large and
robust quantized charge.
