Robust midgap states in band-inverted junctions under electric and magnetic fields
Several IV-VI semiconductor compounds made of heavy atoms, such as Pb1-xSnxTc, may undergo band-inversion at the L point of the Brillouin zone upon variation of their chemical composition. This inversion gives rise to topologically distinct phases, characterized by a change in a topological invarian...
| Autores: | , , |
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| Formato: | artículo |
| Fecha de publicación: | 2018 |
| País: | España |
| Recursos: | Universidad Complutense de Madrid (UCM) |
| Repositorio: | Docta Complutense |
| Idioma: | inglés |
| OAI Identifier: | oai:docta.ucm.es:20.500.14352/12185 |
| Acesso em linha: | https://hdl.handle.net/20.500.14352/12185 |
| Access Level: | acceso abierto |
| Palavra-chave: | 538.9 Topological crystalline insulator Hgte quantum-wells Interface states Phase-transition Heterojunctions Pb1-Xsnxte Gap Supersymmetry Spectroscopy Contact Física de materiales Física del estado sólido 2211 Física del Estado Sólido |
| Resumo: | Several IV-VI semiconductor compounds made of heavy atoms, such as Pb1-xSnxTc, may undergo band-inversion at the L point of the Brillouin zone upon variation of their chemical composition. This inversion gives rise to topologically distinct phases, characterized by a change in a topological invariant. In the framework of the k.p theory, band-inversion can be viewed as a change of sign of the fundamental gap. A two-band model within the envelope-function approximation predicts the appearance of midgap interface states with Dirac cone dispersions in band-inverted junctions, namely, when the gap changes sign along the growth direction. We present a thorough study of these interface electron states in the presence of crossed electric and magnetic fields, the electric field being applied along the growth direction of a band-inverted junction. We show that the Dirac cone is robust and persists even if the fields are strong. In addition, we point out that Landau levels of electron states lying in the semiconductor bands can be tailored by the electric field. Tunable devices are thus likely to be realizable, exploiting the properties studied herein. |
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