Suchergebnisse

3 pages, 1 figure.-- PACS nrs.: 73.21.La, 73.22.-f, 73.20.At, 71.15.Ap.-- Presented as poster communication to TNT 2008: Trends in NanoTechnology (Oviedo, Spain, Sep 1-5, 2008). ; The interface states of all-metallic carbon nanotube quantum dots are studied based on a tight-binding approach and a Green's function matching technique. We have found that depending on the type of metallic tube, the energy of interface states may show an oscillatory behavior. We identify these as steamming from Friedel oscillations. We comment on the possible implications of this finding on other physical properties, such as stability during the growth of nanotube junctions and magnetic interaction through carbon nanotubes. ; We acknowledge financial support by the ETORTEK (NANOMAT) program of the Basque government, the Intramural Special Project (Ref. No. 2006601242), the Spanish Ministerio de Ciencia y Tecnología (Grants No. Fis 2007-66711-C02-C01 and MAT2006-06242) and the European Network of Excellence NANOQUANTA (NM4-CT-2004-500198). ; Peer reviewed

Proceedings of the XXXVII International School of Semiconducting Compounds, Jaszowiec 2008. ; Interface states of all-metallic carbon nanotube quantum dots and superlattices are studied within a tight-binding model. We focus on achiral systems made by connecting armchair (n; n) and zigzag (2n; 0) tubes with a full ring of n pentagon-heptagon topological defects. We show that the coupling between interface states, which arise from the topological defects, re°ects the existence of the Friedel oscillations in the (n; n) tube, with an unusually large decay exponent. We expect this interaction to be important for the understanding of other physical properties, such as selective dot growth, magnetic interaction through carbon tubes or optical spectroscopy of interface states. ; We acknowledge financial support by the ETORTEK (NANOMAT) program of the Basque government, the Intramural Special Project (Ref. 2006601242), the Spanish Ministerio de Ciencia y Tecnologia (Grants No. Fis 2007-66711-C02-C01 and MAT2006-06242), JCCM Grant No. PAI08-0067-2673 and the European Network of Excellence NANOQUANTA (NM4-CT-2004-500198). ; Peer reviewed