Dr. Liu presents Chemical principles of N-doped nanographenes and topological superconductors

Chemical principles of N-doped nanographenes and topological superconductors

Shi-Xia Liu

Department of Chemistry, Biochemistry and Pharmaceutical Sciences, W. Inäbnit Laboratory for Molecular Quantum Materials and WSS Research Centre for Molecular Quantum Systems, University of Bern, Bern, Switzerland

Carbon-based functional nanomaterials, particularly graphene, have attracted a lot of attention due to their promising applications in nanoelectronics, environmental science, energy storage, quantum information science, and biosensors. Among them, nitrogenated polycyclic aromatic hydrocarbons (N-PAHs) are of paramount importance in terms of fine-tuning the band gap, optical and electrical properties, and charge transport. On-surface self-assembly and chemical reactions have become an ideal platform to attain such nanomaterials. We have thus set ourselves the task of preparing a variety of N-PAH precursors with different structural symmetries and functional groups by judicious chemical design. A range of nanostructures, including 1D N-doped graphene nanoribbons (GNRs) and highly symmetric 2D Kagome nanographens with desired functions have been synthesized via surface-assisted C-C coupling reactions [1–4], and directly visualized by scanning tunneling microscopy and atomic force microscopy. More remarkably, it turns out that N-PAHs can self-assemble into nanostructures via H-bonds and/or halogen bonds, whereby different charge/spin states can be manipulated at the nanoscale [5–9]. It would allow us to explore organic molecules on different superconducting substrates for the development of topological quantum bits.       

This presentation will focus on chemical principles of N-doped nanomaterials and gate-tunable topological superconductivity in a 2D electron spin lattice based on our collaborative work on self-assembly and chemical reactions on various surfaces.

[1] Mateo, L. M. et al. (2020), Angew. Chem. Int. Ed., 59, 1334.

[2] Pawlak, R. et al. (2020), J. Am. Chem. Soc., 142, 12568.

[3] Pawlak, R. et al. (2021), Angew. Chem. Int. Ed., 60, 8370.

[4] Kolly, I. et al. (2026), Small Sci., 6, e70288.

[5] Kocic, N. et al. (2015), Nano Lett.,15, 4406

[6] Li, C. et al. (2023), Nat. Commun.,14, 5956.

[7] Li, C. et al. (2025), ACS Nano, 19, 3403.

[8] Pawlak, R. et al. (2025), Nano Lett., 25,15206.

[9] Li, C. et al. (2026), Nat. Commun.,17, 8406.