Modulating Charge-Density Wave Order and Superconductivity from Two Alternative Stacked Monolayers in a Bulk 4Hb-TaSe2 Heterostructure via Pressure

Two-dimensional (2D) van der Waals heterostructures (VDWHs) containing a charge-density wave (CDW) and superconductivity (SC) have revealed rich tunability in their properties, which provide a new route for optimizing their novel exotic states. The interaction between SC and CDW is critical to its properties; however, understanding this interaction within VDWHs is very limited. A comprehensive in situ study and theoretical calculation on bulk 4Hb-TaSe2 VDWHs consisting of alternately stacking 1T-TaSe2 and 1H-TaSe2 monolayers are investigated under high pressure. Surprisingly, the superconductivity competes with the intralayer and adjacent-layer CDW order in 4Hb-TaSe2 , which results in substantially and continually boosted superconductivity under compression. Upon total suppression of the CDW, the superconductivity in the individual layers responds differently to the charge transfer. Our results provide an excellent method to efficiently tune the interplay between SC and CDW in VDWHs and a new avenue for designing materials with tailored properties.

Automated summary

This study investigates the interaction between superconductivity (SC) and charge-density wave (CDW) in 2D van der Waals heterostructures (VDWHs), specifically in bulk 4Hb-TaSe2 consisting of alternating 1T-TaSe2 and 1H-TaSe2 monolayers. Surprisingly, the superconductivity competes with the CDW order in 4Hb-TaSe2, resulting in enhanced superconductivity under compression. The results provide a method to efficiently control the interplay between SC and CDW in VDWHs.