Cubic C₂₀: An intrinsic superconducting carbon allotrope

Abstract Finding intrinsic carbon superconductor is an interesting topic. Based on density functional first-principles calculations, we first study the phonon-mediated superconductivity in a cubic metallic allotrope, namely sc-C20, which has been synthesized experiment. The electron-phonon coupling accurately computed with Wannier interpolation method. By solving Eliashberg equations, predict that sc-C20is superconductor, without introducing any guest atoms or doping, whose transition temperature determined to be about 24 K. Our findings enrich family of carbon-based superconductors.