Observation of Electronic Strong Correlation in VTe_{2}-2sqrt[3]×2sqrt[3] Monolayer

Area of Science:

• Condensed Matter Physics
• Materials Science
• 2D Materials

Background:

• Strong electron correlation is key in 2D materials, particularly transition metal dichalcogenides (TMDs).
• Charge Density Wave (CDW) states in TMD monolayers often exhibit a star of David period.

Purpose of the Study:

• Investigate the VTe2 monolayer's unique 2sqrt[3]×2sqrt[3] CDW period.
• Understand the interplay of CDW transition and electron correlation in VTe2.

Main Methods:

• Scanning tunneling microscopy and spectroscopy (STM/STS).
• Density functional theory (DFT) calculations with on-site Hubbard U corrections.

Main Results:

• Observed dimerization of neighboring Te-Te and V-V atoms during the CDW transition.
• Identified a Mott-like full gap at the Fermi energy (EF) due to strong correlation effects.
• Attributed the Mott phenomenon to the combined effects of CDW transition and on-site Coulomb interactions.

Conclusions:

• VTe2 monolayer provides a novel platform for exploring Mott physics in 2D systems.
• The unique CDW period in VTe2 influences its electronic properties and correlation effects.