2026, Interlayer Valley Coupling and Hybridized Excitons in Twisted van der Waals Bilayers with Broken Translational Symmetry , Advanced Materials.

2026, Interlayer Valley Coupling and Hybridized Excitons in Twisted van der Waals Bilayers with Broken Translational Symmetry , Advanced Materials.

Abstract:

Twisted van der Waals (vdW) bilayers provide a powerful platform for engineering moiré potentials and interlayer coupling, enabling access to otherwise hidden quantum degrees of freedom. At large twist angles, the loss of translational symmetry allows intralayer and interlayer valley momenta to be connected by Umklapp processes, in principle permitting unconventional intervalley coupling. However, direct experimental evidence of such couplings in twisted vdW bilayers with broken translational symmetry has been limited. Here we observe interlayer coupling between the K and −K valleys in twisted MoS₂ bilayers by detecting intense photoluminescence from high-energy interlayer hybridized excitons. These hybridized excitons are absent in commensurate twisted MoS₂ homobilayers and display an almost vanishing valley Zeeman splitting, indicative of strong mixing between intralayer and interlayer excitonic states. This hybridization gives rise to an unusual magnetic-field-dependent valley polarization in excitons with distinct spin configurations. With increasing temperature, the hybridized excitons detune and their energies approach those of intralayer excitons, revealing a sensitive interplay between moiré coupling and thermal effects. Our results uncover a key role of broken translational symmetry in excitons of twisted MoS₂ bilayers and open a route to exploring quantum phenomena in aperiodic twisted MoS₂ materials.

Keywords: Twisted van der Waals bilayers, translational symmetry breaking, moiré quasicrystal, interlayer valley coupling, hybridized exciton.

Link: http://doi.org/10.1002/adma.73772

Advanced Materials - 2026 - Xie - Interlayer Valley Coupling and Hybridized Excitons in Twisted van der Waals Bilayers With.pdf