Precise Tuning of Band Structures and Electron Correlations by van der Waals Stacking of One-dimensional W₆Te₆ Wires.

Abstract

Stacking of two-dimensional (2D) van der Waals (vdW) atomic sheets has been established as a powerful approach to fabricating new materials with broad versatilities and emergent functionalities. Here we demonstrate a bottom-up approach to fabricating isolated single W₆Te₆ wires and their lateral assemblies, offering a unique platform for investigating the elegant role of vdW coupling in 1D systems with atomic precision. We find experimentally and theoretically a single W₆Te₆ wire is a 1D semiconductor with a band gap of ∼60 meV, and a semiconductor-to-metal transition takes place upon interwire vdW stacking. The metallic multiwires exhibit strong Tomonaga-Luttinger liquid characteristics with the correlation parameter <i>g</i> varying from <i>g</i> = 0.086 for biwire to <i>g</i> = 0.136 for six-wire assemblies, all much reduced from the Fermi liquid regime (<i>g</i> = 1). The present study demonstrates wire-by-wire vdW stacking is a versatile means for fabrication of 1D systems with tunable electronic properties.