Shaffique Adam, NUS
Moiré patterns are well known in the visual arts and textile industries — the term comes from the textured patterns seen in mohair silk fabrics. It arises whenever two periodic structures are superimposed giving new periodicities. Remarkably, applying these ideas to atomically thin materials, the coupling between the layers enables designer materials where material properties like bandwidth, electron velocity, and band topology can be controllably altered. With more than 1,000 possible “easily exfoliatable” materials to play with, this opens up the possibility of making billions of designer band structures with promising applications to both fundamental science and technology.
In this tutorial, I will first discuss the history and remarkable recent progress in this area — in less than 15 years since the first isolation of two-dimensional materials, our experimental colleagues are now able to tune the twist angle between adjacent atomic monolayers to within 0.1 degrees. This enables, for example, changing the electronic bandwidth by a factor of 1000, or the strength of correlations by a factor of 100. In the second part of this talk, I will pick up on this idea of correlations in twisted 2D materials and discuss some of the many open problems in the field.
This work is supported by the Singapore National Science Foundation Investigator Award (NRF-NRFI06-2020-0003).
About the presenter
AI Shaffique Adam is currently an Associate Professor, Yale-NUS College and an NRF Fellow. A/Prof Adam is an expert in the theoretical physics of Dirac systems. Within FLEET, he is working on gaining an understanding of the electronic transport and other properties of novel Dirac semimetals, as well as the conventional insulator to topological insulator transition in such systems.