Superconductivity in topological Ψ-graphene

Area of Science:

• Materials Science
• Condensed Matter Physics
• Theoretical Chemistry

Background:

• Graphene's typical Dirac cones lead to absent electronic density at the Fermi energy, preventing intrinsic superconductivity.
• Introducing pentagonal and heptagonal rings into graphene's hexagonal structure breaks symmetry and modifies electronic properties.

Purpose of the Study:

• To investigate the theoretical superconducting properties of a novel graphene allotrope, Ψ-graphene.
• To explore the impact of structural modifications on graphene's electronic and superconducting behavior.

Main Methods:

• Theoretical calculations of electronic band structure and phonon modes.
• Computation of the Eliashberg function to evaluate electron-phonon coupling.
• Analysis of structural stability and adsorption properties of NO molecules on Ψ-graphene.

Main Results:

• The metastable Ψ-graphene monolayer forms type-II Dirac cones, shifting Fermi surfaces.
• Strong electron-phonon coupling was predicted, with a calculated superconducting transition temperature of 22 K.
• The Ψ-graphene-NO adsorption system demonstrated good dynamic stability.

Conclusions:

• The modified graphene structure, Ψ-graphene, shows potential for intrinsic superconductivity.
• Topological graphene allotropes warrant further investigation for their superconducting applications.
• Theoretical predictions suggest a pathway towards designing novel superconducting materials.