Electron-phonon interaction and superconductivity of potassium-intercalated hexagonal boron nitride

Potassium intercalated hexagonal boron nitride is known to be metallic and was recently synthesized using a straightforward molten-metal-assisted approach. First-principles calculations suggest that the resulting compound consists of one or two potassium layers between hBN layers. The potassium electron disperses in space, forming a nearly free 2D electron gas between hBN layers with a corresponding parabolic conduction band. We explore the coupling between the polar hBN optical phonons couple and the 2D electron gas and assess the potential for superconductivity using density functional perturbation theory and Migdal-Eliashberg theory.