Valley properties of moiré-trapped Interlayer excitons in WSe₂/WS₂ moiré superlattices

Moiré superlattices formed by stacking atomic layers of transition metal dichalcogenide semiconductors have emerged as a class of artificial photonic and electronic materials that can be engineered to realize fascinating many-body states. In this study, we investigate one- and two-exciton interlayer exciton states confined in the moiré potential of WSe₂/WS₂ twisted bilayers and investigate their spin-valley behavior. The interrogations of the valley-dependent selection rule and excitonic g factor distinguish excitons from different atomic registries within the superlattice. Valley polarization of the single exciton sites is found to be highly sensitive to optical excitation power and weak external magnetic field. These observations reflect the intriguing interplay between the singly and doubly occupied exciton sites, as well as the role of exchange interactions for moiré excitons. Our work provides insights into exciton relaxation and formation within moiré superlattices, offering a pathway to engineering quantum optoelectronic platforms with such systems.