Electron-phonon coupling in the high-pressure hcp phase of xenon: A first-principles study

The electronic properties, lattice dynamics, and electron-phonon coupling (EPC) of the high-pressure hexagonal close-packed (hcp) phase of Xe have been examined by first-principles pseudopotential plane-wave calculations based on the density-functional perturbation theory. An electron topological transition is found around $200\phantom{\rule{0.3em}{0ex}}\mathrm{GPa}$. The EPC is shown to increase with pressure, reaching a maximum at $215\phantom{\rule{0.3em}{0ex}}\mathrm{GPa}$ with a predicted superconducting critical temperature of $0.04\phantom{\rule{0.3em}{0ex}}\mathrm{K}$ assuming a nominal Coulomb repulsion parameter $({\ensuremath{\mu}}^{*})$ of 0.1. The superconductivity is correlated with the nesting of Fermi surface. Investigation of the lattice dynamics reveals that acoustic vibrations, especially the longitudinal mode, dominate the EPC. The EPC strength was found to be strongly spatially anisotropic and localized.