Exciton Superposition across Moiré States in a Semiconducting Moiré Superlattice.

Moiré superlattices of semiconducting transition metal dichalcogenides enable unprecedented spatial control of electron wavefunctions, leading to emerging quantum states. The breaking of translational symmetry further introduces a new degree of freedom: high symmetry moiré sites of energy minima behaving as spatially separated quantum dots. We demonstrate the superposition between two moiré sites by constructing a trilayer WSe/monolayer WS moiré heterojunction. The two moiré sites in the first layer WSe interfacing WS allow the formation of two different interlayer excitons, with the hole residing in either moiré site of the first layer WSe and the electron in the third layer WSe. An electric field can drive the hybridization of either of the interlayer excitons with the intralayer excitons in the third WSe layer, realizing the continuous tuning of interlayer exciton hopping between two moiré sites and a superposition of the two interlayer excitons, distinctively different from the natural trilayer WSe.