Topological Superconductivity in Heavily Doped Single-Layer Graphene.

Area of Science:

• Condensed Matter Physics
• Materials Science
• Quantum Phenomena

Background:

• Superconductivity (SC) is known in graphene multilayers, but its presence in single-layer graphene (SLG) is uncertain.
• Theoretical models suggest SLG could host SC at its van Hove singularity, but experimental validation is lacking.
• Doping SLG beyond the van Hove singularity was recently achieved, opening new research avenues.

Purpose of the Study:

• To investigate the emergence of unconventional superconductivity in heavily doped single-layer graphene.
• To explore the potential for topological superconductivity in SLG using specific doping methods.
• To determine the influence of different dopants on the stability of d-wave superconductivity in SLG.

Main Methods:

• Numerical simulations using a random-phase approximation framework.
• Angle-resolved photoemission spectroscopy (ARPES) for structural model derivation.
• First-principles calculations to assess various dopant effects.

Main Results:

• Prediction of robust d + id topological superconductivity in Tb-intercalated SLG with a critical temperature (Tc) up to 600 mK.
• Identification that dopants altering SLG lattice symmetry are detrimental to the d-wave state.
• Demonstration of heavy doping of SLG past the van Hove singularity via Tb intercalation.

Conclusions:

• Tb-intercalated SLG is a promising candidate for realizing topological superconductivity.
• The findings provide crucial insights for guiding future experimental efforts in monolayer graphene superconductivity.
• Understanding dopant effects is key to stabilizing and controlling superconductivity in 2D materials.