2021/05/31 by Zongxiu Wu, Kunliang Bu, Wenhao Zhang +8 · 48 citations
Chemistry · Materials Science · Physics and Astronomy · #2D Materials and Applications #Artificial intelligence #Band gap #Chemistry #Computer science #Condensed matter physics #Crystallography #Electronic and Structural Properties of Oxides #Enhanced Data Rates for GSM Evolution #Iron-based superconductors research #Materials science #Nuclear magnetic resonance #Order (exchange) #Physics #Scanning tunneling microscope #Stacking #cond-mat.mtrl-sci #cond-mat.str-el
paper · pdf · doi:10.1103/physrevb.105.035109
published in Physical review. B./Physical review. B 105(3) (American Physical Society) · 9 pages, 8 figures
openalex publication_date 2022/01/06 · arxiv created 2022/01/10 · arxiv updated 2022/01/11 · openalex created_date 2022/01/26 · openalex updated_date 2026/08/06
New theoretical proposals and experimental findings on transition metal dichalcogenide 1T\ensuremath-TaS2 have revived interest in its possible Mott insulating state. We perform a comprehensive scanning tunneling microscopy and spectroscopy experiment on different single-step areas in pristine 1T\ensuremath-TaS2. After accurately determining the relative displacement of the Star of David superlattices in two layers, we find that different stacking orders can correspond to a similar large-gap spectrum on the upper terrace. When the measurement is performed away from the step edge, the large-gap spectrum can always be maintained. The stacking order seems to rarely disturb the large-gap spectrum in the ideal bulk material. We conclude that the large insulating gap is from the single-layer property, which is a correlation-induced Mott gap based on the single-band Hubbard model. Specific stacking orders can perturb the state and induce a small-gap or metallic spectrum for a limited area around the step edge, which we attribute to a surface and edge phenomenon. Our work provides more evidence about the stacking-order effect on the electronic state and deepens our understanding of the Mott insulating state in 1T\ensuremath-TaS2.