The opening of a gap in single-layer graphene is often ascribed to the breaking of the equivalence between the two carbon sublattices. It is shown by angle-resolved photoemission spectroscopy that Ir- and Na-modified graphene grown on the Ir(111) surface presents a very large unconvengrown on the Ir(111) surface presents a very large unconventional gap that can be described in terms of a phenomenological massless Dirac model. The consequences and differences of this model are discussed in comparison to the standard massive gap model, and the conditions under which such anomalous gap can arise from a spontaneous symmetry breaking are investigated.
Massless Dirac cones in graphene: Experiments and theory
Papagno M;PACILE', Daniela;
2014-01-01
Abstract
The opening of a gap in single-layer graphene is often ascribed to the breaking of the equivalence between the two carbon sublattices. It is shown by angle-resolved photoemission spectroscopy that Ir- and Na-modified graphene grown on the Ir(111) surface presents a very large unconvengrown on the Ir(111) surface presents a very large unconventional gap that can be described in terms of a phenomenological massless Dirac model. The consequences and differences of this model are discussed in comparison to the standard massive gap model, and the conditions under which such anomalous gap can arise from a spontaneous symmetry breaking are investigated.I documenti in IRIS sono protetti da copyright e tutti i diritti sono riservati, salvo diversa indicazione.
