Dokument: Van Hove Singularities and Resonant Tunneling in Carbon Nanotubes
| Titel: | Van Hove Singularities and Resonant Tunneling in Carbon Nanotubes | |||||||
| URL für Lesezeichen: | https://docserv.uni-duesseldorf.de/servlets/DocumentServlet?id=2274 | |||||||
| URN (NBN): | urn:nbn:de:hbz:061-20030521-000274-6 | |||||||
| Kollektion: | Dissertationen | |||||||
| Sprache: | Englisch | |||||||
| Dokumententyp: | Wissenschaftliche Abschlussarbeiten » Dissertation | |||||||
| Medientyp: | Text | |||||||
| Autor: | Hügle, Sascha [Autor] | |||||||
| Dateien: |
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| Beitragende: | Prof. Dr. Egger, Reinhold [Gutachter] Prof. Dr. Janssen, Hans-Karl [Gutachter] | |||||||
| Stichwörter: | Nanoroehre, Quantenpunkt, Zustandsdichte,Unordnung, van Hove Singularitaet, resonantes Tunneln, LuttingerFluessigkeit, Leitwert, Doppelbarriere, Coulomb-Blockadenanotube, quantumdot, density of states, disorder, van Hove singularity, resonanttunneling, Luttinger liquid, conductance, double barrier, Coulombblockade | |||||||
| Dewey Dezimal-Klassifikation: | 500 Naturwissenschaften und Mathematik » 530 Physik | |||||||
| Beschreibungen: | Die Arbeit behandelt van Hove Singularitaeten in der Tunnelzustandsdichte von ungeordneten mehrwandigen Kohlenstoff-Nanoroehren sowie elektronischen Transport durch einen Quantenpunkt in einer einwandigen Kohlenstoff-Nanoroehre.We present a theory for the van Hove singularity (VHS) in the tunneling density of states (TDOS) of disordered multichannel quantum wires, in particular multi-wall carbon nanotubes. We assume close-by gates which screen off electron-electron interactions. Diagrammatic perturbation theory within the non-crossing approximation yields analytical expressions governing the disorder-induced broadening and shift of VHS\'s as new subbands are opened. This problem is nontrivial because the (lowest-order) Born approximation breaks down close to the VHS. Interestingly, compared to the bulk case, the boundary TDOS shows drastically altered VHS, even in the clean limit. Further, a numerically exact dynamical quantum Monte Carlo approach has been developed and applied to transport through a double barrier in a Luttinger liquid with arbitrary transmission. For strong transmission, we find broad Fabry-Perot Coulomb blockade peaks, with a lineshape parametrized by a single parameter, but at sufficiently low temperatures, non-Lorentzian universal lineshapes characteristic of coherent resonant tunneling emerge, even for strong interactions. For weak transmission, our data supports a correlated sequential tunneling picture instead of the conventional incoherent process. | |||||||
| Lizenz: |  Urheberrechtsschutz | |||||||
| Fachbereich / Einrichtung: | Mathematisch- Naturwissenschaftliche Fakultät » WE Physik | |||||||
| Dokument erstellt am: | 21.05.2003 | |||||||
| Dateien geändert am: | 12.02.2007 | |||||||
| Promotionsantrag am: | 21.05.2003 | |||||||
| Datum der Promotion: | 21.05.2003 |
