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 Tc based on electron-phonon interaction is 3.02 K,while the unconventional Tc primarily caused by spin fluctuation is 1.7 K.We hypothesize that the remaining hexagonal C6structure of biphenylene may not be conducive to the formation of perfect Fermi nesting,leading to a lower Tc.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.