Band Structure of Carbon Nanotubes

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Band Structure of Carbon Nanotubes
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Discovery

• First observed by Iijima (1991)
• Multiwalled

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Arc-discharge evaporation
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Laser ablation
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Chemical vapour deposition
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Armchair tube
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Zigzag tube
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Chiral tubes
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Graphite
Bravais lattice
Dispersion relation
1947 P.R. Wallace
Tight-binding, nearest neighbour
Reciprocal space
Equi-energy regions
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5,5 Armchair tube
Bravais lattice
Reciprocal lattice
Periodic boundary conditions
Dispersion relation
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9,0 Zigzag tube
Bravais lattice
Reciprocal lattice
Periodic boundary conditions
Dispersion relation
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10,0 Zigzag tube
Reciprocal lattice
Metallic zigzag tubes satisfy
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Are they real metals?
Zigzag tube
Armchair tube
Stable against Peierls distortion Armchair tube
conduct ballistically gt10mm
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Ballistic transport
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Applications

• Nano electronics (FETs)
• Spintronics
• AFM tips
• Composite materials