Charge density wave surface reconstruction in a van der Waals layered material

Abstract

Surface reconstruction plays a vital role in determining the surface electronic structure and chemistry of semiconductors and metal oxides. However, it has been commonly believed that surface reconstruction does not occur in van der Waals layered materials, as they do not undergo significant bond breaking during surface formation. In this study, we present evidence that charge density wave (CDW) order in these materials can, in fact, cause CDW surface reconstruction through interlayer coupling. Using density functional theory calculations on the 1T-TaS2 surface, we reveal that CDW reconstruction, involving concerted small atomic displacements in the subsurface layer, results in a significant modification of the surface electronic structure, transforming it from a Mott insulator to a band insulator. This new form of surface reconstruction explains several previously unexplained observations on the 1T-TaS2 surface and has important implications for interpreting surface phenomena in CDW-ordered layered materials.

arXiv comment20 pages, 6 figures (Supplementary Information: 5 Pages, 3 figures)

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Cited by in corpus (5)

• Origin of Distinct Insulating Domains in the Layered Charge Density Wave Material 1T-TaS2
• Interlayer Hopping between Surface Mott Insulator and Bulk Band Insulator in layered 1T-TaS_{2}
• Topical review: the nature of the ground state and possibility of a quantum spin liquid in 1T metal dichalcogenides
• Interlayer coupling driven phase evolution in hyperbolic $1T$-TaS${}_2$
• Dual Charge-Density-Waves in Two-dimensional DyTe3 and Their Distinct Impacts on Magneto-Transport Properties