Possible Superconductivity in Biphenylene

A new two-dimensional allotrope of carbon known as biphenylene has been synthesized. Building on previous research investigating the superconductivity of octagraphene with a square-octagon structure, we conduct a systematic study on possible superconductivity of biphenylene with partial square-octagon structure. First-principle calculations are used to fit the tight-binding model of the material and to estimate its superconductivity. We find that the conventional superconducting transition temperature T_c based on electron-phonon interaction is 3.02 K, while the unconventional T_c primarily caused by spin fluctuation is 1.7 K. We hypothesize that the remaining hexagonal C₆ structure of biphenylene may not be conducive to the formation of perfect Fermi nesting, leading to a lower T_c. The superconducting properties of this material fall between those of graphene and octagraphene, and it lays a foundation for achieving high-temperature superconductivity in carbon-based materials.