Prediction of π -electrons mediated high-temperature superconductivity in monolayer LiC 12 .

Prediction and synthesis of two-dimensional high transition temperature ( T C ) superconductors is an area of extensive research. Based on calculations of the electronic structures and lattice dynamics, we predict that graphene-like layered monolayer LiC 12 is a π -electrons mediated Bardeen-Cooper-Schrieffer-type superconductor. Monolayer LiC 12 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- T C superconductivity in LiC 12 . The T C can reach to 41 K under an applied 10% biaxial tensile strain based on the anisotropic Eliashberg equation. Our results show that monolayer LiC 12 is a good candidate as π -electrons mediated electron-phonon coupling high- T C superconductor.