Nanoscale Modulation of Flat Bands via Controllable Charge-Density-Waves Defects in 4Hb-TaS2

Abstract

Electron correlation is a main driver of exotic quantum phases and their interplay. The 4Hb-TaS2 system, possessing intrinsic heterostructure of 1T- and 1H-TaS2 monolayers, offers a unique opportunity to control electron correlation by distorting the atomic lattice or tuning interlayer coupling. Here, we investigated intrinsically deformed charge-density-waves (CDW) in the 1T layer of 4Hb-TaS2 to elucidate and control their effects on flat bands using scanning tunneling microscopy and spectroscopy (STM/S) combined with first-principles calculations. We identified two types of CDW defects: Type 1 has structural distortion and locally suppressed flat bands, while Type 2 features an increased flat band filling factor of intact CDW structure. Density functional theory calculations indicate that a sulfur vacancy in the 1T layer distorts the CDW structure and gives rise to a Type 1, whereas a sulfur vacancy in the 1H layer reduces the interlayer charge transfer and lead to a Type 2. Furthermore, we demonstrated creating and erasing individual CDW defects via STM manipulation. Our findings provide a pathway to not only tune flat bands but also selectively manipulate the interaction between CDW, the atomic lattice, and interlayer coupling in strongly correlated systems with atomic precision.

arXiv comment12 pages, 4 figures

References in corpus (19)

• Magic-angle graphene superlattices: a new platform for unconventional superconductivity
• Fractional quantum Hall states at zero magnetic field
• Fractional quantum Hall effect in the absence of Landau levels
• A metallic mosaic phase and the origin of Mott insulating state in 1T-TaS2
• Nanoscale manipulation of the Mott insulating state coupled to charge order in 1T-TaS2
• Mottness versus unit-cell doubling as the driver of the insulating state in 1T-TaS2
• Visualization of Topological Boundary Modes Manifesting Topological Nodal-Point Superconductivity
• Superconducting Transitions in Flat Band Systems
• Robust charge-density wave strengthened by electron correlations in monolayer 1T-TaSe2 and 1T-NbSe2
• Orbital density wave order and electronic correlation driven insulating 1T-TaS2 monolayer
• Roles of the Narrow Electronic Band near the Fermi Level in 1T-TaS${}_2$-Related Layered Materials
• Heterogeneous Ta-dichalcogenide bilayer: heavy fermions or doped Mott physics?
• Do Se vacancies electron dope monolayer FeSe?
• Enhanced superconductivity in few-layer TaS${}_2$ due to healing by oxygenation
• Inducing and tuning Kondo screening in a narrow-electronic-band system
• Coexistence of Quasi-two-dimensional Superconductivity and Tunable Kondo Lattice in a van der Waals Superconductor
• Symmetry breaking and spin-orbit coupling for individual vacancy-induced in-gap states in MoS2 monolayers
• Atomically-precise engineering of spin-orbit polarons in a kagome magnetic Weyl semimetal
• Understanding the flat band in 1T-TaS2 using a rotated basis