Moiré-Induced Electronic Reconstruction in van der Waals Heterobilayer PtSe₂/PtTe₂.

Abstract

van der Waals heterostructures composed of a few atomic layers have attracted significant attention in the condensed matter physics community. Although interlayer bonding is weak, effects such as moiré modulation, charge redistribution, and electronic hybridization can substantially modify the band structure and interlayer coupling. In this work, we investigate heterostructures composed of few-layer PtSe₂ and PtTe₂ by using first-principles calculations implemented within density functional theory (DFT) and angle-resolved photoemission spectroscopy (ARPES). While both materials are Dirac semimetals in the bulk form, they undergo a transition to semiconducting states in the few-layer limit. These heterostructures allow systematic examination of how dimensional confinement and interfacial interactions influence band structure and interlayer coupling. Our combined ARPES measurements and DFT calculations indicate the presence of electronic hybridization at the interface. The interlayer coupling in PtSe₂/PtTe₂ is associated with flat-band features and valence-band splitting induced by both inversion symmetry breaking and spin-orbit coupling. Furthermore, the local density of states indicates metallic behavior at the MM site while it remains semiconducting at MX and XX sites with the band gap of 0.40 and 0.25 eV, respectively. Further analysis shows that the electronic hybridization and charge transfer between PtSe₂ and PtTe₂ are sensitive to the interlayer distance, which is consistent with moiré characteristics. These results highlight how interfacial interactions govern the electronic properties of vdW heterostructures.