Topologically induced semiconductivity in icosahedral Al-Pd-Re and its approximants surface

Autor(en)

Marian Krajci, Juergen Hafner

Abstrakt

We demonstrate that the opening of a semiconducting band-gap in the electronic spectrum of the i-Al-Pd-Re quasicrystal and its approximants is due to the formation of a topological band-gap, in analogy to the band-gap found in the FeSi (B20) structure. In both systems we have identified a network of linear chains of alternating Si(Al) and transition-metal (TM) atoms extending along twofold symmetry directions. In i-Al-Pd-Re the chains of alternating Al and TM atoms extend from a center of the pseudo-Mackay (M) cluster over the surface of the Bergman cluster to the center of another neighboring M cluster. Substitutional Al Pd defects and a fragmentation of the chains by phason defects lead to the formation of localized states in the band-gap. The band-gap of the real i-Al-Pd-Re quasicrystal is filled by localized states. The i-Al-Pd-Re quasicrystal thus behaves as a disordered semiconductor. © 2007 The American Physical Society. Society.

Organisation(en)

Computergestützte Materialphysik

Externe Organisation(en)

Slovenian Academy of Sciences and Arts

Journal

Physical Review B

Band

75

Anzahl der Seiten

18

ISSN

1098-0121

DOI

https://doi.org/10.1103/PhysRevB.75.024116

Publikationsdatum

2007

Peer-reviewed

Ja

ÖFOS 2012

1030 Physik, Astronomie

Link zum Portal

https://ucrisportal.univie.ac.at/de/publications/37592993-bbbb-4248-aae4-5d138a7f1eee