Modulation of electronic structure via dual moiré patterns in twisted 1T-TaSe₂

We investigate a twisted bilayer of 1T-TaSe₂ (twist angle [Formula: see text]) using scanning tunneling microscopy and spectroscopy, revealing that the coexisting twisted atomic lattice and charge density wave (CDW) superlattice generate a dual moiré structure with distinct electronic modulation effects: The topographic moiré pattern stems from atomic lattice twisting modulating CDW intensity, while the twisted CDW superlattice drives a continuous insulator-to-metal transition, as evidenced by electronic gap evolution from large to metallic states. Density functional theory calculations show this transition arises from twist-induced changes in star of David motif stacking. Using the moiré-period gap map as the interlayer potential [Formula: see text], we construct a continuum model via its Fourier components [Formula: see text], finding that [Formula: see text] mediates multiple interlayer scattering processes that produce numerous superposition states manifesting as split flat-band pairs with distinct energy gaps. This work elucidates a CDW-twist-based mechanism for electronic control in 1T-TaSe₂ and provides insights into Mott physics and complex electronic phases in related materials.