Alternating Superconducting and Charge Density Wave Monolayers within Bulk 6R-TaS₂

Area of Science:

• Materials Science
• Condensed Matter Physics
• Solid State Chemistry

Background:

• Van der Waals (vdW) heterostructures offer a pathway to design novel materials.
• Current limitations restrict vdW heterostructures to only a few stacked layers.

Purpose of the Study:

• To report a bulk vdW material with coexisting superconductivity and charge density waves (CDW).
• To investigate the properties of a novel 6R-TaS₂ phase.

Main Methods:

• Synthesis of bulk vdW heterostructure via phase transition of 1T-TaS₂ to 6R at 800 °C.
• Measurement of superconducting transition temperature (T_c).
• First-principles calculations to understand the coexistence of superconductivity and CDW.

Main Results:

• A bulk vdW material of 1H TaS₂ interlayered with 1T TaS₂ was successfully synthesized.
• The 6R-TaS₂ exhibited a superconducting transition at 2.6 K, surpassing the T_c of bulk 2H-TaS₂.
• First-principles calculations confirmed the coexistence of superconductivity and CDW properties.

Conclusions:

• The novel 6R-TaS₂ demonstrates the potential for creating bulk heterostructures with emergent properties.
• The coexistence arises from the amalgamation of properties from adjacent 1H (superconducting) and 1T (CDW) monolayers.
• This work expands the design principles for advanced vdW materials.