Nanostructured Carbon Allotropes with Weyl-like Loops and Points

Area of Science:

• Condensed Matter Physics
• Materials Science
• Quantum Chemistry

Background:

• Carbon allotropes are extensively studied for their unique properties.
• Topological band properties in carbon materials are underexplored due to weak spin-orbit coupling (SOC).
• Existing research focuses on structural, electronic, and chemical properties, overlooking topological aspects.

Purpose of the Study:

• To investigate the potential of conjugated p-orbital interactions in carbon allotropes for generating topological band structures.
• To demonstrate the formation of Weyl-like semimetals in the absence of SOC.
• To explore the emergence of surface states in these novel topological carbon materials.

Main Methods:

• First-principles calculations were employed to study the electronic band structure.
• Tight-binding modeling was used to analyze the topological properties.
• An interpenetrated graphene network (IGN) was used as a model system.

Main Results:

• Conjugated p-orbital interactions can lead to topological band structures, creating Weyl-like semimetals without SOC.
• The interpenetrated graphene network (IGN) exhibits symmetry-protected Weyl-like loops with linear dispersion.
• Breaking inversion symmetry transforms loops into Weyl-like points, resulting in surface flat bands and Fermi arcs.

Conclusions:

• Topological band structures can be realized in carbon allotropes through p-orbital interactions, independent of SOC.
• The identified topological carbon materials, featuring Weyl-like features, offer new possibilities in condensed matter physics.
• These materials hold potential for applications in catalysis and advanced electronic devices.