Direct Observation of Dirac Fermion Cloning in Graphene/SiC Heterostructure

The electronic coupling between graphene internal layers and the coupling between graphene and substrates could generate lots of interesting physics phenomenon, specially, the twisting of the different graphene layers and the lattice mismatch between graphene and the substrates could generate the cloning of the Dirac cones, and these Dirac Fermion cloning can modulate the electron properties dramatically and form Mott insulator, super-conductivity, Ferro-magnetism, Wigner Crystal, Anomalous Hall effect, etc.
In this work, we measured the electronic structures of the BLG/SiC heterostructure. Apart from the duplicated Dirac cone from the superlattice, 24 Dirac cones in the 1^st BZ are clearly observed using angle-resolved photoemission spectroscopy (ARPES). These 24 Dirac cones are directly generated from the coupling between graphene layers and the substrate lattice. Furthermore, tight-binding simulation is used to understand the properties of those cloned Dirac Fermions. This work could pave the way for understanding the formation of the Dirac Fermion Cloning and foresee some electron properties generated by the Dirac Fermion Cloning.