Phonon-mediated superconductivity in silicene predicted by first-principles density functional calculations

We predict that electron-doped silicene is a good two-dimensional electron-phonon superconductor under biaxial tensile strain by first-principles calculations within the rigid-band approximation. Superconductivity transition temperature of electron-doped silicene can be increased up to above 10 K by 5% tensile strain. Band structures, phonon dispersive relations, and Eliashberg functions are calculated for detailed analysis. The strong interaction between acoustic phonon modes normal to the silicene plane and the increasing electronic states around the Fermi level induced by tensile strain is mainly responsible for the enhanced critical temperature.