The superconducting energy gap in the hole-doped graphene beyond the Migdal's theory

TL;DR

This paper investigates how non-adiabatic effects influence the superconducting energy gap in hole-doped graphene, revealing that vertex corrections suppress superconductivity and significantly alter the phase in two-dimensional materials.

Contribution

It extends Eliashberg theory beyond Migdal's approximation to analyze non-adiabatic effects in superconductivity of doped graphene.

Findings

Non-adiabatic effects suppress the superconducting gap.

Vertex corrections influence Coulomb depairing correlations.

Superconducting phase is notably affected by non-adiabatic effects.

Abstract

In this work we analyze impact of non-adiabatic effects on the superconducting energy gap in the hole-doped graphene. By using the Eliashberg formalism beyond the Migdal's theorem, we present that the non-adiabatic effects strongly influence the superconducting energy gap in the exemplary boron-doped graphene. In particular, the non-adiabatic effects, as represented by the first order vertex corrections to the electron-phonon interaction, supplement Coulomb depairing correlations and suppress the superconducting state. In summary, the obtained results confirm previous studies on superconductivity in two-dimensional materials and show that the corresponding superconducting phase may be notably affected by the non-adiabatic effects.