Chair of Theoretical Chemistry, TU Dresden, Germany
Abstract: The discovery of graphene initiated an immense research effort in the field of two-dimensional (2D) crystals. Graphene shows extraordinary high stability, intriguing electronic, including topological, properties, and chemical inertness. Soon it was clear that 2D crystals can be formed from virtually all layered materials by top-down (exfoliation…), but also bottom-up (chemical vapor deposition…) approaches. The family of 2D materials contains a lot of remarkable phenomena, for example 2D semiconductors that get metallic when the number of layers is increased, 2D topological insulators, and 2D metals.
It is somewhat less known that graphene represents also the prototype 2D polymer. 2D polymers (also 2D covalent-organic frameworks – 2D COFs) are a rather new family of synthetic 2D crystals where molecular units are stitched together with strong bonds. This offers a regular crystal lattice and thus materials comprising all collective phenomena that are known from solid state physics, however, with a much richer diversity due to the essentially infinite number of molecules that can be considered. A recent breakthrough was the discovery of chemical coupling reactions that achieve full conjugation between the constituting molecules, which is the precondition for the formation of 2D semiconductors with ballistic transport properties.
For the 2D polymers I will to focus on structural diversity: while mathematically, 11 tilings are possible in two-dimensions (the so-called Kepler nets), nature offers much less structural diversity in crystalline 2D materials. By picking suitable molecular building units we can form lattices with structural topologies that impose, in turn, electronic topologies. One of the examples that I will highlight is the kagome structure, which produces both Dirac points and flat bands.
Biography: Prof. Heine is Full Professor of Theoretical Chemistry at TU Dresden and Adjunct Professor of Theoretical Physics at Jacobs University Bremen, Germany. In 1995 he received his diploma (physics) at TU Clausthal, Germany, and in 1999 his PhD (physics) at TU Dresden. After postdoctoral stages at University of Bologna (Italy) and University of Geneva (Switzerland) he obtained his venia legendi in Physical Chemistry at TU Dresden in 2006. In 2008 he started his research group as Associate Professor at Jacobs University Bremen, where he was promoted to Full Professor in 2011. From 2015-2018 he held the Chair of Theoretical Chemistry at Leipzig University, and in 2018 he accepted the offer for the Chair of Theoretical Chemistry associated with a group leader position a Helmholtz Center Dresden-Rossendorf. His research interest is the computational science of nanostructured materials, in particular of two-dimensional crystals and molecular frameworks. Prof. Heine is a highly cited author with more than 290 peer-reviewed articles, an h-index of 54 (ISI) and he gave more than 50 talks at international workshops and conferences.