Optical investigation of strongly correlated electrons

Atac Imamoglu, ETH Zurich

Two dimensional semiconductors subject to a Moiré potential provide a fertile ground for exploration of strongly correlated phases, ranging from kinetic magnetism, through fractional Chern insulators to unconventional superconductivity. In the first set of experiments , we studied topologically trivial moire bands with vanishing exchange interactions; here we observed ferromagnetic correlations stemming from a kinetic mechanism. The focus of the second set of experiments was on interplay between interactions and topology in twisted MoTe2 homobilayer. In this system, we demonstrated optical control of ferromagnetism in general and topological Chern insulator states in particular.