Coexistence of multiple electronic and phononic nodal lines in a two-dimensional macroporous carbon material

Abstract

Investigations into topological materials typically emphasize either electronic or phononic properties in isolation, often disregarding their coexistence, which could restrict the full realization of their practical applications. Here, we investigate HOD-graphene, an emergent macroporous carbon material featuring a unique configuration of hexagonal, octagonal, and dodecagonal carbon rings. This distinctive structure imparts exceptional mechanical properties to the material. Using a combination of first-principles calculations and symmetry analysis, we demonstrate that HOD-graphene hosts multiple nodal lines within both its electronic and phononic spectra. For the electronic bands, three nodal lines and several Dirac points manifest near the Fermi energy, generating unconventional electronic properties and distinct topological characteristics. Likewise, the phonon spectrum displays pronounced nodal lines, intricately associated with the material's vibrational modes. Our findings provide a promising platform for exploring the coexistence of electronic and phononic multiple nodal lines in two-dimensional materials, opening avenues for realizing exotic quantum phenomena.