Carbon nanotubes with their remarkable mechanical and electronic properties play a major role in the design of next generations nanoelectronic and nanomechanical devices. The conductivity of single wall nanotubes (SWNT) is mostly determined by the chirality of the tubes. Depending on their chirality, they could be conductor, semiconductor as well as insulator. It is also widely known that the conductivity of the nanotubes changes due to deformations such as uniaxial compressive or tensile. Such deformations at elevated temperatures can modify the band gap of the nanotubes, causing conducting-semiconducting-insulator transitions of the nanotubes. In this study, we will present our Order N,Parallel Tight-Binding Molecular Dynamics simulation study of (10*10) and (17*0) carbon nanotubes. Classical tight-binding methods solve the Schrodinger equation through diagonalization which leads to order N cubed behavior in cost, N being the number of atoms. In order to study the structure and electronic properties of carbon nanotubes we have implemented a parallel order N-scaling emprical tight-binding molecular dynamics algorithm based on divide and conquer approach. In this talk, we will report on the performance characteristics of our algorithms along with the study of of armchair (n,n) and (n,0) isolated single wall carbon nanotubes. Structural stability, energetics and electronic density of states of (10*10) and (17*0) carbon nanotubes will be reported for pristine and for various uniaxial compressive and tensile loads at elevated temperatures.
Department of Physics, Middle East Technical University
Inonu Bulvari, Ankara 06531 TURKEY
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