Curvature dependence of electric and thermal conductivity in carbon nanotubes. Wan-Ju Li Phys 570X Proposal presentation 04/22/2009. Outline. Motivation Introduction Conductivities under strain Summary. Motivation.
Curvature dependence of electric and thermal conductivity in carbon nanotubes
Phys 570X Proposal presentation
M: number of transport channels
G: electric conductance
E: energy of electrons
When E lies inside a band gap we can use quantum mechanical penetration or thermal activation transport to obtain the transmission coefficient and then get electric conductance.
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Example of a molecular dynamics simulation in a simple system: deposition of a single Cu atom on a Cu (001) surface. Each circle illustrates the position of a single atom;
Potential form for our problem
Parameters, except R and D, are chosen to fit the cohesive energy, lattice constant, and bulk modulus of diamond. For carbon we choose R=1.95A D=0.15A, where R is chosen to include only the first neighbor shell.
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Thermal conductivity λ is related to the thermal current correlation function.
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Michael C H Wu and Jang-Yu Hsu,
nanotechnology 20 145401(2009)
+ change of gap by strain
Molecule dynamics simulation
R. Heyd. et al, PRB 55,6820(1997)