High-temperature surface superconductivity in topological flat-band systems

TL;DR

This paper demonstrates that topologically protected flat bands on surfaces of nodal fermionic systems can induce high-temperature surface superconductivity due to their infinite density of states, with potential applications in multilayered graphene.

Contribution

It reveals that flat bands on surfaces significantly enhance superconductivity, providing a new mechanism for high-temperature surface superconductivity in topological systems.

Findings

Surface flat bands promote surface superconductivity.

Critical temperature depends linearly on pairing interaction.

Example provided in multilayered graphene with rhombohedral stacking.

Abstract

We show that the topologically protected flat band emerging on a surface of a nodal fermionic system promotes the surface superconductivity due to an infinitely large density of states associated with the flat band. The critical temperature depends linearly on the pairing interaction and can be thus considerably higher than the exponentially small bulk critical temperature. We discuss an example of surface superconductivity in multilayered graphene with rhombohedral stacking.