Illustration from Scientific Research

Schematic shows the strong correlation induced moire exciton site transition. At charge neutrality, the interlayer excitons occupy R_h^X site where the optical selection rule for the interlayer exciton renders the co-circularly polarized PL emission (left). When doped with electrons, the Coulomb repulsion ( U_{e-ex} ) between electrons and interlayer excitons makes the interlayer excitons transfer to the R_h^h site which is the secondary energy minimum of the moire potential (right). Consequently, the polarization switching of the interlayer excitons occurs into the linearly-polarized PL. Correspondingly, the enhanced Pauli blocking is observed by both steady-state and ultrashort optical measurements.

DOI