Direct identification of Mott Hubbard band pattern beyond charge density wave superlattice in monolayer 1T-NbSe<sub>2</sub>.
basic_science · Level V
Where this comes from
- Record sourced from PubMed, PMID 33785747.
- Also identified by DOI 10.1038/s41467-021-22233-w and PMC identifier 8010100.
- Licence recorded as CC BY.
- The licence permits redistribution, so the abstract is shown in full and the full text is available from the publisher.
Abstract
Understanding Mott insulators and charge density waves (CDW) is critical for both fundamental physics and future device applications. However, the relationship between these two phenomena remains unclear, particularly in systems close to two-dimensional (2D) limit. In this study, we utilize scanning tunneling microscopy/spectroscopy to investigate monolayer 1T-NbSe<sub>2</sub> to elucidate the energy of the Mott upper Hubbard band (UHB), and reveal that the spin-polarized UHB is spatially distributed away from the dz<sup>2</sup> orbital at the center of the CDW unit. Moreover, the UHB shows a √3 × √3 R30° periodicity in addition to the typically observed CDW pattern. Furthermore, a pattern similar to the CDW order is visible deep in the Mott gap, exhibiting CDW without contribution of the Mott Hubbard band. Based on these findings in monolayer 1T-NbSe<sub>2</sub>, we provide novel insights into the relation between the correlated and collective electronic structures in monolayer 2D systems.