主持人：章一奇 特聘研究员

联系人：傅琦 (fuqi@iphy.ac.cn)

Abstract:

In the first part of the talk, I will introduce a novel theory of scanning tunneling microscopy (STM). which is fundamental for the proper description of STM measurements of strongly correlated molecules on surfaces. This theory goes beyond traditional STM theories based on one-electron canonical DFT orbitals and reconciles the long-standing dispute over whether molecular orbitals can be observed in STM.

In the second part of the talk, I will focus on the emerging field of quantum molecular Π magnets, which can nowadays be synthesized with atomic precision employing UHV on-surface synthesis. I will briefly introduce basic mechanisms leading to Π magnetism and we will focus on antiferromagnetically frustrated spin rings. Namely, we will show that a strong interaction between radical centers in spin rings of different sizes leads to fluctuation of the total number of unpaired electrons and non-trivial antiferromagnetic order that extends beyond the Heisenberg picture. We will show that the electronic structure of these spin rings is governed by the concept of 4n/4n+2 Hückel (anti)aromaticity for even-membered rings, while for odd-membered rings, it possesses a highly degenerate frustrated magnetic ground state.

Brief CV of Prof. Pavel Jelinek:
Pavel Jelinek is a senior researcher at the Institute of Physics of the Czech Academy of Sciences. He received his Ph.D. degree in Material and Physical Engineering from the Czech Technical University in 2001. From 2001 to 2005, he was a postdoctoral fellow at the Autonomous University of Madrid, focusing on the theoretical description of transport phenomena at the nanoscale. In 2008, he was a Fulbright fellow at Arizona State University. In 2014-2015, he was appointed as a visiting Professor at the Graduate School of Engineering, Osaka University. From 2017, he has also been appointed as an associated professor at CATRIN, Palacky University in Olomouc, Czechia. In 2009, he established the research NANOSURF group, which strongly benefits from the unique synergy between experiment and theory. His research focuses on both experimental and theoretical aspects of on-surface UHV synthesis of low-dimensional molecular structures and their characterization using advanced low-temperature UHV scanning probe microscopy. In particular, he is interested in theory of SPM and the electronic structure of strongly correlated low-dimensional molecular systems on surfaces.