Prediction of π-electrons mediated high-temperature superconductivity in monolayer LiC12.

Prediction and synthesis of two-dimensional high transition temperature (TC) superconductors is an area of extensive research. Based on calculations of the electronic structures and lattice dynamics, we predict that graphene-like layered monolayer LiC12 is a π-electrons mediated Bardeen-Cooper-Schrieffer-type superconductor. Monolayer LiC12 is theoretically stable and expected to be synthesized experimentally. From the band structures and the phonon dispersion spectrum, it is found that the saddle point of π-bonding bands induces large density of states at the Fermi energy level. There is strongly coupled between the vibration mode in the in-plane direction of the lithium atoms and the π-electrons of carbon atoms, which induces the high-TC superconductivity in LiC12. The TC can reach to 41 K under an applied 10% biaxial tensile strain based on the anisotropic Eliashberg equation. Our results show that monolayer LiC12 is a good candidate as π-electrons mediated electron-phonon coupling high-TC superconductor.