Electron-phonon coupling in graphene placed between magnetic Li and Si layers on cobalt

Superconductivity in two-dimensional materials remains largely unexplored and attracts much attention. Although graphene is not a superconductor, adsorption of alkali metals on its surface may enhance electron-phonon coupling (EPC) sufficiently to induce superconductivity. Here, using photoemission spectroscopy, the authors study the electronic structure and EPC in a Li-doped graphene monolayer weakly bonded to a cobalt substrate. It is shown that EPC is high enough to create superconductivity in graphene, however the nonmagnetic graphene layer is clamped between two oppositely magnetized atomic layers. This condition makes the studied system a promising platform for understanding the influence of magnetic environment on superconductivity at low dimensions.