New two-dimensional flat band materials: B₃C₁₁O₆ and B₃C₁₅O₆

Area of Science:

• Condensed Matter Physics
• Materials Science
• Quantum Chemistry

Background:

• Flat-band physics is gaining attention for its unique properties and applications.
• Two-dimensional (2D) materials offer novel platforms for exploring exotic electronic phenomena.

Purpose of the Study:

• To introduce and characterize two novel 2D monolayers, B3C11O6 and B3C15O6.
• To investigate the origin and properties of nearly flat bands (NFBs) in these materials.
• To explore the potential of these monolayers for realizing novel quantum phases.

Main Methods:

• Computational material discovery and characterization.
• Calculations of formation energies to assess thermodynamic stability.
• Phonon spectra and molecular dynamics simulations for dynamic stability.
• Electronic band structure calculations to identify and analyze NFBs.

Main Results:

• B3C11O6 and B3C15O6 monolayers are energetically, dynamically, and thermodynamically stable.
• NFBs were identified in both monolayers, originating from distinct structural features (extended kagome sublattice vs. localized five-ring states).
• The NFB in B3C11O6 exhibits spin splitting, leading to a ferromagnetic metallic state.

Conclusions:

• The discovered B3C11O6 and B3C15O6 monolayers are promising candidates for flat-band physics research.
• These materials provide new lattice types for hosting flat bands and NFBs.
• The study highlights the tunability of electronic properties in 2D materials through structural design.