Other Research Highlights

Topological insulators are three-dimensional crystals with protected conducting states on their surface. We proved theoretically that they have "higher-order" cousins that have protected metallic states on crystal hinges. We collaborated with experimental groups to show that elementary bismuth is such a higher-order topological insulator.

"Higher-Order Topological Insulators", Science Advances 4, eaat0346 (2018)

"Higher-Order Topology in Bismuth", Nature Physics 14, 918 (2018)

The quench dynamics of quantum many-body systems can reveal fundamental properties of the system and is often studied in cold-atom experiments. To simulate such dynamics, we employed matrix-product-states-based methods for both closed and open quantum systems, in particular in the context of many-body localization.

"Signatures of Many-Body Localization in a Controlled Open Quantum System", PRX 7, 011034 (2017)

"Dynamics of a Many-Body-Localized System Coupled to a Bath", PRL 116, 160401 (2016)

"Observation of many-body localization of interacting fermions in a quasirandom optical lattice", Science 349, 842-845 (2015)

Artificial Lattices, not naturally occurring but created in the lab, can exhibit novel and intriguing phenomena. A particularly prominent example of recent years that our group studies is twisted bilayer graphene, which, for the right ‘magic’ angles, shows both correlated insulating behavior and superconductivity. Novel physics can emerge when placing atoms on a material in a periodic fashion using an STM tip. Depositing magnetic atoms on the surface of a (conventional) superconductor, for example, can lead to the emergence of topological bands formed by the resulting Shiba bound states.

Key Publications:

• "Two-dimensional Shiba lattices as a possible platform for crystalline topological superconductivity", Nature Physics 19, 1848 (2023)