THEOS-MARVEL seminar: Marco Gibertini

Engineering emergent topological phases in van der Waals heterostructures

Prof. Marco Gibertini

University of Modena and Reggio Emilia, Italy

Despite the huge expansion in the family of 2D materials, quantum spin Hall and Chern insulators have remained rare and elusive, as most monolayers are topologically trivial. Still, combining such trivial 2D materials into van der Waals heterostructures offers combinatorially vast opportunities to realize emergent topological order. In this seminar, I will present several strategies to engineer topological heterostructures out of trivial insulating layers, and demonstrate how the resulting  phase can be actively controlled by external means. On one side, I will show that the Chern number of a magnetic heterostructure can be reversibly switched by rotating the magnetization using an external magnetic field. Moreover, I propose to achieve a non-volatile electric-field control of a quantum spin Hall phase by combining a trivial 2D insulator with a ferroelectric monolayer. All theoretical scenarios are validated by accurate first-principles simulations and supported by a systematic screening of 2D materials databases for realistic experimental platforms.

About the speaker

Marco Gibertini is a condensed-matter physicist working on the theory and simulation of materials, with an emphasis on their magnetic, topological, and vibrational properties in two dimensions. After obtaining his PhD at Scuola Normale Superiore (Pisa, Italy) in 2013 working with Rosario Fazio, Marco Polini and Fabio Taddei, he moved as a post-doc in the group of Nicola Marzari at the École Polytechnique Fédérale de Lausanne (EPFL, Switzerland). Marco joined the group of Alberto Morpurgo at the University of Geneva (Switzerland) in 2017 as an Ambizione fellow of the Swiss National Science Foundation. In 2019 Marco was awarded a Levi-Montalcini grant by the Italian Ministry for University and Research to become assistant professor at the University of Modena and Reggio Emilia (Italy). Since 2022 he is Associate Professor of condensed-matter theory at the same university.