Time: 10:00 AM Jun 3 (Tuesday), 2025

Host: Prof. Jinbo Peng

Venue: TDLI Meeting Room N400

Tencent meeting link:  https://meeting.tencent.com/dm/h18kGn0D1wd7   Meeting ID: 692674184 , no password

Abstract:

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, 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. It allows 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.

Biography:

Shi-Xia Liu was born in China on March 26, 1970. She earned her PhD in Chemistry from Lanzhou University in 1998. As an Alexander von Humboldt Research Fellow, she conducted research at the University of Siegen (Germany) from 1999 to 2000. Following this, she joined the group of Prof. Silvio Decurtins at the University of Bern (Switzerland), where she worked as a senior researcher from 2000 to 2015. From 2016 to 2020, she was a lecturer in the Department of Chemistry, Biochemistry and Pharmaceutical Sciences at the University of Bern. In October 2020, she received her Venia Legendi after successfully completing her habilitation. Since October 2024, she has acted as the head of both the W. Inäbnit Laboratory for Molecular Quantum Materials and the Werner Siemens Research Center for Molecular Quantum Systems at Bern University.

Her current research focuses on the preparation and functionalization of large π-extended conjugates, including fused electron donor-acceptor ensembles designed to regulate charge-transfer directions. She also explores the surface-assisted synthesis of graphene-like materials and their applications in molecular (opto)electronics. With the support of the Werner Siemens grant, her major efforts are currently devoted to the development of organic molecular systems that can form spin lattices and switchable topological superconductors on various superconducting substrates, aiming to advance the design of topological qubits for quantum computing.