Dirac Fermions in Graphene with Stacking Fault Induced Periodic Line Defects

The exploration of carbon phases with intact massless Dirac fermions in the presence of defects is critical for practical applications to nanoelectronics. Here, we identify by first-principles calculations that the Dirac cones can exist in graphene with stacking fault (SF) induced periodic line defects. These structures are width (n)-dependent to graphene nanoribbon and are thus termed as (SF)-graphene. The electronic properties reveal that the semimetallic features with Dirac cones occur in (SF)-graphene with n = 3m + 1, where m is a positive integer, and then lead to a quasi-one-dimensional conducting channel. Importantly, it is found that the twisted Dirac cone in the (SF)₄-graphene is tunable among type-I, type-II, and type-III through a small uniaxial strain. The further stability analysis shows that (SF)-graphene is thermodynamic stable. Our findings provide an artificial avenue for exploring Dirac Ffermions in carbon-allotropic structures in the presence of defects.