Tunable Electron Correlation in Epitaxial TaS₂ Spirals

Tantalum disulfide (1T-TaS₂), being a Mott insulator with strong electron correlation, is highlighted for diverse collective quantum states in the two-dimensional (2D) lattice, including charge density wave (CDW), spin liquid, and unconventional superconductivity. The Mott physics embedded in the 2D triangular CDW lattice has raised debates on stacking-dependent properties because interlayer interactions are sensitive to van der Waals (vdW) spacing. However, control of interlayer distance remains a challenge. Here, we study spiral lattices in the epitaxial TaS₂ spirals to probe collective properties with tunable interlayer interactions. A scalable synthesis of epitaxial TaS₂ spirals is presented.[1] A more than 50%-increased interlayer spacing enables prototype decoupled monolayers for enhanced electronic correlation exhibiting Mott physics at room temperature and a simplified system to explore diverse collective properties in vdW materials.