Speaker
Description
Moiré materials produced by stacking monolayers with small relative twist angles are of intense current interest for the range of correlated electron phenomena they exhibit and for their high degree of experimental controllability. Controlling moiré to realize exotic quantum phase of matter is important for both fundamental science research and future application to quantum information sciences. This talk focus on the fractional Chern insulator phase, the analogy of fractional quantum Hall effect in the absence of external magnetic fields.
The common wisdom is to engineer material to approach Landau level limit to stabilize fractional Chern insulators. This talk will disprove such common lore by showing a new theory (ideal flatband theory) which emphasizes the fundamental importance of quantum geometries of wavefunctions. The new theory points to a large family of flatband systems that stabilize fractional Chern insulators exactly beyond the conventional Landau level limit. It has a wide range of application to 2D material design, including twisted bilayer graphene, moiré TMD material, vortex lattice systems and others. It had direct implication for the recently experimental observed fractional Chern insulator in twisted bilayer graphene samples.
