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Tight-binding model for the band dispersion in rhombohedral topological insulators over the whole Brillouin zone

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Autor(es):
Acosta, Carlos Mera ; Lima, Matheus P. ; da Silva, Antonio J. R. ; Fazzio, A. ; Lewenkopf, C. H.
Número total de Autores: 5
Tipo de documento: Artigo Científico
Fonte: PHYSICAL REVIEW B; v. 98, n. 3, p. 8-pg., 2018-07-05.
Resumo

We put forward a tight-binding model for rhombohedral topological insulator materials with the space group D-3d(5)(R (3) over barm). The model describes the bulk band structure of these materials over the whole Brillouin zone. Within this framework, we also describe the topological nature of surface states, characterized by a Dirac conelike dispersion and the emergence of surface projected bulk states near to the Dirac point in energy. We find that the breaking of the R-3 symmetry as one moves away from the Gamma point has an important role in the hybridization of the p(x), p(y) , and p(z) atomic orbitals. In our tight-binding model, the latter leads to a band mixing matrix element ruled by a single parameter. We show that our model gives a good description of the strategies/mechanisms proposed in the literature to eliminate and/or energy shift the bulk states away from the Dirac point, such as stacking faults and the introduction of an external applied electric field. (AU)

Processo FAPESP: 14/12357-3 - Tansistor baseado em spintrônica: caracterização topológica e transporte balístico em isolantes topológicos
Beneficiário:Carlos Augusto Mera Acosta
Modalidade de apoio: Bolsas no Brasil - Doutorado