| Abstract: | Transition-metal dichalcogenides (TMDs) with mixed polytypes offer a unique platform for studying the interplay between correlated electron physics and superconductivity. The TMD 4Hb-TaS 2 is a naturally occurring alternating stack of 1T and 1H TaS 2 layers, in which the 1T layers host a correlated insulating state with a strong chiral charge-density wave (CDW), while the 1H layers are metallic and become superconducting at low temperatures. Understanding how these distinct electronic phases interact across the interface is essential for uncovering the emergent phenomena observed in this material.
Using nano-ARPES, we directly resolve the electronic structure associated with different surface terminations, enabling us to isolate the contribution of individual 1T and 1H layers within the heterostructure. This spatially selective approach allows us to probe the momentum-resolved fingerprints of the CDW and the superconducting layers independently.
We show that interlayer coupling plays a central role in shaping the chiral CDW order in the 1T layers, modifying both its spectral signatures and its local handedness. Our results demonstrate how the stacking architecture of 4Hb-TaS 2 governs its intertwined electronic orders and highlight nano-ARPES as a powerful tool for disentangling the layer-specific physics in van der Waals heterostructures. |