Engineering Dirac Materials: Metamorphic InAs1-xSbx/InAs1-ySby Superlattices with Ultralow Bandgap.
Nano Lett
; 18(1): 412-417, 2018 01 10.
Article
em En
| MEDLINE
| ID: mdl-29266950
ABSTRACT
Quasiparticles with Dirac-type dispersion can be observed in nearly gapless bulk semiconductors alloys in which the bandgap is controlled through the material composition. We demonstrate that the Dirac dispersion can be realized in short-period InAs1-xSbx/InAs1-ySby metamorphic superlattices with the bandgap tuned to zero by adjusting the superlattice period and layer strain. The new material has anisotropic carrier dispersion the carrier energy associated with the in-plane motion is proportional to the wave vector and characterized by the Fermi velocity vF, and the dispersion corresponding to the motion in the growth direction is quadratic. Experimental estimate of the Fermi velocity gives vF = 6.7 × 105 m/s. Remarkably, the Fermi velocity in this system can be controlled by varying the overlap between electron and hole states in the superlattice. Extreme design flexibility makes the short-period metamorphic InAs1-xSbx/InAs1-ySby superlattice a new prospective platform for studying the effects of charge-carrier chirality and topologically nontrivial states in structures with the inverted bandgaps.
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Coleções:
01-internacional
Base de dados:
MEDLINE
Idioma:
En
Revista:
Nano Lett
Ano de publicação:
2018
Tipo de documento:
Article
País de afiliação:
Estados Unidos