A CNT QD is formed when electrons are confined to a small region within a carbon nanotube. This is normally accomplished by application of a voltage to a gate electrode, dragging the valence band of the CNT down in energy, thereby causing electrons to pool in a region in the vicinity of the electrode. Experimentally this is accomplished by laying a CNT on a silicon dioxide surface, sitting on a dopedsilicon wafer. This can be done by chemical vapor deposition using carbon monoxide.[1] The silicon wafer serves as the gate electrode. Metallic leads can then be laid over the nanotube in order to connect the CNT QD up to an electrical circuit.
Electronic structureedit
The CNT QD has interesting properties as a result of the strong correlation between the confined electrons. In addition to this the electrons possess orbital angular momentum, as is characteristic of CNT electrons. spin–orbit coupling has also been shown to be significant in these systems.[2][3] These properties are often probed by connecting the nanotube to two metallic leads and measuring the conductance of the system.
Many-body systemsedit
The CNT QD connected to metallic leads constitutes a genuine many-body system, due to the electron correlations. Therefore, Wilson's Numerical renormalization group is often used to study the CNT QD. The CNT QD is modelled as an Anderson-type model, which can be reduced by Schrieffer-Wolff transformation to an effective Kondo-type model at low temperature.
Other nanotube systemedit
Similar mesoscopic devices have been constructed from elements other than carbon. So called copper nanotubes (CuNTs), developed by the Chinese Academy of Sciences,[4] are fabricated by closely aligning individual copper atoms on a surface.
^Yang D, Meng G, Zhang S, Hao Y, An X, Wei Q, Ye M, Zhang L (2007). "Electrochemical synthesis of metal and semimetal nanotube–nanowire heterojunctions and their electronic transport properties". Chemical Communications. 7 (17): 1733–1735. doi:10.1039/b614147a. PMID 17457424. S2CID 2534957.
January 01, 1970
carbon, nanotube, quantum, this, article, needs, additional, citations, verification, please, help, improve, this, article, adding, citations, reliable, sources, unsourced, material, challenged, removed, find, sources, news, newspapers, books, scholar, jstor, . This article needs additional citations for verification Please help improve this article by adding citations to reliable sources Unsourced material may be challenged and removed Find sources Carbon nanotube quantum dot news newspapers books scholar JSTOR April 2009 Learn how and when to remove this message A carbon nanotube quantum dot CNT QD is a small region of a carbon nanotube in which electrons are confined Contents 1 Formation 2 Electronic structure 3 Many body systems 4 Other nanotube system 5 See also 6 NotesFormation editA CNT QD is formed when electrons are confined to a small region within a carbon nanotube This is normally accomplished by application of a voltage to a gate electrode dragging the valence band of the CNT down in energy thereby causing electrons to pool in a region in the vicinity of the electrode Experimentally this is accomplished by laying a CNT on a silicon dioxide surface sitting on a doped silicon wafer This can be done by chemical vapor deposition using carbon monoxide 1 The silicon wafer serves as the gate electrode Metallic leads can then be laid over the nanotube in order to connect the CNT QD up to an electrical circuit Electronic structure editThe CNT QD has interesting properties as a result of the strong correlation between the confined electrons In addition to this the electrons possess orbital angular momentum as is characteristic of CNT electrons spin orbit coupling has also been shown to be significant in these systems 2 3 These properties are often probed by connecting the nanotube to two metallic leads and measuring the conductance of the system Many body systems editThe CNT QD connected to metallic leads constitutes a genuine many body system due to the electron correlations Therefore Wilson s Numerical renormalization group is often used to study the CNT QD The CNT QD is modelled as an Anderson type model which can be reduced by Schrieffer Wolff transformation to an effective Kondo type model at low temperature Other nanotube system editSimilar mesoscopic devices have been constructed from elements other than carbon So called copper nanotubes CuNTs developed by the Chinese Academy of Sciences 4 are fabricated by closely aligning individual copper atoms on a surface See also editCadmium free quantum dot Carbon nanotube Carbon quantum dot Graphene quantum dot Optical properties of carbon nanotubesNotes edit B Zheng et al Nano Letters 2 895 2002 F Kuemmeth et al Nature 452 2008 M Galpin et al PRB 81 075437 2010 Yang D Meng G Zhang S Hao Y An X Wei Q Ye M Zhang L 2007 Electrochemical synthesis of metal and semimetal nanotube nanowire heterojunctions and their electronic transport properties Chemical Communications 7 17 1733 1735 doi 10 1039 b614147a PMID 17457424 S2CID 2534957 Retrieved from https en wikipedia org w index php title Carbon nanotube quantum dot amp oldid 1141439569, wikipedia, wiki, book, books, library,
