Johannes Lischner
(Imperial College London)

Beautiful moiré patterns can be created by stacking and twisting two-dimensional crystals, such as graphene or transition metal dichalcogenides. One of the most fascinating discoveries in recent years is that electrons are strongly affected by these moiré patterns and often exhibit completely unexpected behaviour. For example, twisted bilayer graphene – composed of two (semi-)metallic graphene layers – was observed to exhibit correlated insulator states as well as superconductivity at a magic twist angle of 1.1 degrees. In my talk, I will describe my group’s efforts to understand the electronic properties of moiré materials from an atomistic perspective which is challenging because of the large unit cells in these systems (often containing thousands of atoms). To overcome this difficulty, we developed accurate tight-binding models and then incorporate the effects of electron-electron interactions. Based on the atomistic simulations, we also construct effective moiré-scale Hubbard-like models to describe the behaviour at large length scales.

Light Refreshments
will be served at the end of the Seminar
at 17:00 on the terrace of the Leonardo Building

Zoom registration link:
https://zoom.us/meeting/register/tJ0lde2qrTMiHdZZU7TFtkyhSHZT9iFI8IN6