Large angle commensurate moiré crystals in twisted bilayer WSe₂

Superlattice created by homobilayers at larger twist angles (e.g. 21.8 and 38.2) has unveiled intriguing properties such as sharp conductivity peaks and enhanced excitonic peaks ^[1–3]. These large-angle commensurate moiré crystals, with periodicity of order of 1 nm or less, offer a distinguished platform for investigating Umklapp scatterings and interlayer coherent couplings. Using valley-resolved tunneling spectroscopy^[4] in combination with first-principle calculations, we present direct evidence of robust interlayer and intralayer interactions in large-angle twisted bilayer WSe₂ which reasonably explains the transport phenomena observed in this system. This study shows intricate electronic configurations of large angle commensurate WSe₂, close to the VBM, positioning them as promising candidates for gated, precision-tuned optical and transport studies.

References:

[1] Koren, E. et al. Coherent commensurate electronic states at the interface between misoriented graphene layers. Nat. Nanotechnol. 11, 752–757 (2016).

[2] Zhang, L. et al. Twist-angle dependence of moiré excitons in WS2/MoSe2 heterobilayers. Nat. Commun. 11, 5888 (2020).

[3] Ribeiro-Palau, R. et al. Twistable electronics with dynamically rotatable heterostructures. Science 361, 690–693 (2018).

[4] Zhang, C. et al. Probing Critical Point Energies of Transition Metal Dichalcogenides: Surprising Indirect Gap of Single Layer WSe ₂. Nano Lett. 15, 6494–6500 (2015).