Topological Nodal-Net Semimetal in a Graphene Network Structure

Area of Science:

• Condensed Matter Physics
• Materials Science
• Quantum Chemistry

Background:

• Topological semimetals possess unique electronic structures with nodal points, leading to exotic properties.
• These nodal points can be discrete, lines, or rings, influencing bulk band topology.

Purpose of the Study:

• To identify and characterize a distinct type of topological semimetal with a novel nodal manifold.
• To propose realistic material candidates for realizing this new topological state.

Main Methods:

• Ab initio calculations were employed to investigate the electronic structure.
• The study focused on analyzing bulk band topology and surface states.

Main Results:

• A distinct topological semimetal state exhibiting nodal nets (interconnected nodal lines) was identified.
• Two coupled drumhead-like flat bands were found near the Fermi level on the material's surface.
• Potential material realizations include a specific graphene network and a modified carbon nanotube.

Conclusions:

• The discovery expands the known types of nodal manifolds in topological semimetals.
• The identified nodal net semimetal offers a new platform for exploring novel quantum phenomena.