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- Hybridization of topological surface states with a flat band doi link

Auteur(s): Krishtopenko S.

(Article) Publié: Journal Of Physics: Condensed Matter, vol. 32 p.165501 (2020)
Texte intégral en Openaccess : arxiv


Ref HAL: hal-02447824_v1
DOI: 10.1088/1361-648X/ab6741
WoS: 000520157900001
Exporter : BibTex | endNote
Résumé:

We address the problem of hybridization between topological surface states and a non-topological flat bulk band. Our model, being a mixture of three-dimensional Bernevig–Hughes–Zhang and two-dimensional pseudospin-1 Hamiltonian, allows explicit treatment of the topological surface state evolution by continuously changing the hybridization between the inverted bands and an additional ‘parasitic’ flat band in the bulk. We show that the hybridization with a flat band lying below the edge of the conduction band converts the initial Dirac-like surface states into a branch below and one above the flat band. Our results univocally demonstrate that the upper branch of the topological surface states is formed by Dyakonov–Khaetskii surface states, known for HgTe since the 1980s. Additionally we explore an evolution of the surface states and the arising of Fermi arcs in Dirac semimetals when the flat band crosses the conduction band.