Interlayer Valley Coupling and Hybridized Excitons in Twisted van der Waals Bilayers with Broken Translational Symmetry

Twisted van der Waals (vdW) bilayers, characterized by strong moiré effects and interlayer coupling, offer a versatile platform for exploring novel quantum phenomena. At large twist angles, the broken translational symmetry facilitates the alignment of intralayer and interlayer valley momenta through Umklapp scattering, enabling unique intervalley coupling. However, the experimental investigation of such couplings in twisted vdW bilayers with broken translational symmetry remains scarce. Here, we report the observation of interlayer K and −K valley coupling in twisted vdW bilayers with broken translational symmetry, demonstrated by the emergence of strong photoluminescence from high-energy interlayer hybridized excitons. These excitons are absent in commensurate homobilayers and exhibit an almost negligible valley Zeeman effect, attributed to the robust hybridization between intralayer and interlayer excitons. This hybridization drives a unique magnetic-field-dependent valley polarization in excitons with distinct spin states. As temperature increases, the hybridized excitons detune, bringing their energy closer to that of intralayer excitons. These findings highlight the fundamental role of broken translational symmetry in moiré physics and open new avenues for exploring quantum phenomena in aperiodic twisted vdW materials.