Self-Intercalated 1T-FeSe₂ as an Effective Kagome Lattice

Area of Science:

• Condensed Matter Physics
• Materials Science
• Solid-State Chemistry

Background:

• Kagome lattices exhibit unique electronic properties like Dirac cones and flat bands, crucial for studying frustrated geometry, topology, and electron correlation.
• The scarcity of natural kagome materials limits research into these fascinating phenomena.

Purpose of the Study:

• To develop a synthetic route for creating artificial kagome structures.
• To investigate the structural and electronic properties of the synthesized material.

Main Methods:

• Self-intercalation of iron (Fe) atoms into the van der Waals gap of FeSe2 using molecular beam epitaxy.
• Low-temperature scanning tunneling microscopy (STM) for morphological and electronic characterization.
• Theoretical modeling and calculations to understand the observed phenomena.

Main Results:

• Successfully constructed a kagome-like structure with a 2x2 ordered Fe atom intercalation, yielding Fe5Se8.
• STM imaging revealed the kagome morphology arises from the reconstruction of surface Se atoms due to subsurface Fe intercalation.
• Bias-dependent STM and theoretical calculations confirmed the structural origins of the kagome pattern.

Conclusions:

• Demonstrated a viable method for fabricating artificial kagome systems.
• The synthetic approach offers a tunable platform for exploring novel quantum states in correlated materials.