Geometrically Induced Emergent Band in Electronic Structures of van der Waals Moiré Bilayer: PtSe₂/PtTe₂

Van der Waals heterostructures enabled by the stacking of few atomic layers hold attraction for the condensed matter physics community. Though the weak interlayer bonding is through van der Waals force, the interfacial effects, such as electronic hybridization and moiré modulation could lead to emergent phenomena such as superconductivity and novel electronic correlations. Herein, we comprehensively investigated the PtSe₂/PtTe₂ heterostructure using first-principles calculation with density functional theory (DFT) and angle-resolved photoemission spectroscopy (ARPES). Presenting an integrated theoretical-experimental study to elucidate both the geometric and electronic structure of PtSe₂/PtTe₂ heterostructure, highlighting the critical role of geometric buckling and spin-orbit coupling (SOC) effects in modulating the electronic structure. We demonstrate the interlayer coupling in PtSe₂/PtTe₂ can lead to the emergence of exotic band features such as the flat bands and giant valence bands splitting induced both by inversion symmetry breaking and SOC. The local density of states (LDOS) further reveals a transition to metallic behavior at the MM site while remaining semiconductor characteristics at the MX and XX sites with the bandgap of 0.40 and 0.25 eV. These findings establish the prototypical platform for the investigation of electronic phenomena of two-dimensional van der Waals materials.