Reflection by defects in a tight-binding model of nanotubes

Journal Article · Fri Jan 01 04:00:00 UTC 1999 · Physical Review, B: Condensed Matter

DOI:https://doi.org/10.1103/PhysRevB.59.3241· OSTI ID:302809

Kostyrko, T ^[1]; Bartkowiak, M ^[1]; Mahan, G D ^[1]

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1. Solid State Division, Oak Ridge National Laboratory, Oak Ridge, Tennessee 37831-6030 (United States)

We use a transfer-matrix method to study defects in a tight-binding model of carbon nanotubes. We calculate the reflection coefficient {ital R} for a simple barrier created by a pointlike defect of strength {ital E} in armchair (N{sub a},N{sub a}) and zigzag (N{sub a},0) nanotubes for the whole range of energy {omega} and arbitrary number of conducting channels. We find that {ital R} scales at the Fermi level (i.e., {omega}=0) as R=s(E/t){sup 2}/N{sub a}{sup 2} (t being the hopping parameter), where s{approx}1/6 (for the armchair nanotubes) and s{approx}1/2 (for the zigzag nanotubes). We also perform a similar calculation for a {open_quotes}5-77-5{close_quotes} defect and find the results to be like the ones obtained for a strong point defect with E=6t. {copyright} {ital 1998} {ital The American Physical Society}

• OSTI ID: 302809
• Journal Information: Physical Review, B: Condensed Matter, Journal Name: Physical Review, B: Condensed Matter Journal Issue: 4 Vol. 59; ISSN PRBMDO; ISSN 0163-1829
• Country of Publication: United States
• Language: English

Related Subjects

36 MATERIALS SCIENCE
BAND THEORY
CARBON
ELECTRONIC STRUCTURE
FERMI LEVEL
MICROSTRUCTURE
POINT DEFECTS