New exciton resonances in a semiconductor monolayer induced by remote moire potential

When two atomically thin van der Waals layers are stacked, a two-dimensional moire superlattice emerges. While many experiments have reported new optical resonances in transition metal dichalcogenide (TMD) moire superlattices, the microscopic nature of these many-body excited states remains elusive. We take an approach to engineer optical resonances via a remote moire potential in a TMD trilayer. The moire potential is created by a TMD homobilayer with a small twist angle from the commensurate stacking style. The functional layer is another TMD monolayer with a large twist angle with respect to the other layers. Several new resonances emerge in the functional layer. We investigate the possible mechanisms for the formation of the new resonances including strain. Our findings introduce an additional degree of freedom for engineering light–matter interactions in atomically thin semiconductor heterostructures.