Phonon-mediated Superconductivity in Silicene

TL;DR

This paper predicts that electron-doped silicene can become a two-dimensional superconductor with a transition temperature above 10 K under 5% tensile strain, driven by phonon-electron interactions.

Contribution

It demonstrates that biaxial tensile strain enhances superconductivity in silicene, providing first-principles evidence for strain-induced increase in critical temperature.

Findings

Superconductivity in silicene can exceed 10 K with 5% tensile strain.

Strain enhances electron-phonon coupling, especially involving acoustic phonons.

Band structure and phonon calculations elucidate the mechanism of Tc increase.

Abstract

We predict that electron-doped silicene is a good two-dimensional electron-phonon superconductor under biaxial tensile strain by first-principles calculations within rigid band approximation. Superconductivity transition temperature of electron-doped silicene can be increased to be 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.