Realization of topological quantum states in carbon nanostructures has recently emerged as a promising platform for hosting highly coherent and controllable quantum dot spin qubits. However, their adjustable manipulation remains elusive. Here, we report the atomically accurate control of the hybridization level of topologically protected quantum edge states emerging from topological interfaces in bottom-up-fabricated π-conjugated polymers. Our investigation employed a combination of low-temperature scanning tunneling microscopy and spectroscopy, along with high-resolution atomic force microscopy, to effectively modify the hybridization level of neighboring edge states by the selective dehydrogenation reaction of molecular units in a pentacene-based polymer and demonstrate their reversible character. Density functional theory, tight binding, and complete active space calculations for the Hubbard model were employed to support our findings, revealing that the extent of orbital overlap between the topological edge states can be finely tuned based on the geometry and electronic bandgap of the interconnecting region. These results demonstrate the utility of topological edge states as components for designing complex quantum arrangements for advanced electronic devices.

Condensed Matter Physics Center Universidad Autónoma E 28049 Madrid Spain

Departamento de Física de la Materia Condensada Universidad Autónoma E 28049 Madrid Spain

Departamento de Química Orgánica Facultad de Ciencias Químicas Universidad Complutense 28040 Madrid Spain

Faculty of Nuclear Sciences and Physical Engineering Czech Technical University 11519 Prague Czech Republic

IMDEA Nanoscience Campus Universitario de Cantoblanco 28049 Madrid Spain

Institute of Physics of the Czech Academy of Sciences 16200 Prague Czech Republic

Nanomaterials and Nanotechnology Research Center CSIC UNIOVI PA 33940 El Entrego Spain

Regional Centre of Advanced Technologies and Materials Czech Advanced Technology and Research Institute Palacký University 78371 Olomouc Czech Republic

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