Correlated Excitons in TMDC Moiré Superlattice

In strongly correlated electronic systems, Coulomb interactions among electrons dominate over kinetic energy, leading to rich quantum phenomena. Recently, two-dimensional (2D) moiré superlattices of van der Waals materials have emerged as a promising platform to study correlated physics and exotic quantum phases in 2D. In transition metal dichalcogenides (TMDCs) based moiré superlattices, the combination of a large effective mass and strong moiré coupling facilitates the formation of flat bands and strong electronic correlations, leading to a plethora of intriguing correlated states, such as Mott insulators and generalized Wigner crystals. Meanwhile, the strong Coulomb interaction in 2D also leads to tightly bound excitons in TMDCs. These excitons inherit the strong correlation and strongly interact with correlated electrons and other excitons. In this talk, we will discuss how to use optical spectroscopy to investigate excitonic physics and strongly correlated phenomena in the TMDC moiré superlattice, with a particular focus on correlated exciton states arising from strong interactions.