Large value of the electron-phonon coupling parameter(λ=1.15)and the possibility of surface superconductivity at the Be(0001) surface

Abstract

The electron-phonon coupling parameter ${\lambda }_s$ at the Be(0001) surface is measured using angle-resolved photoemission and found to be $1.15\pm 0.1,$ more than four times the bulk Be value ${\lambda }_b=\mathrm{0.24.}\mathrm{}$ This large value for ${\lambda }_s$ may imply the existence of an unusual form of surface superconductivity with a correspondingly large transition temperature.