The strain dependence of the electronic structure and transport properties of (6,0) carbon nanotubes was studied using first-principles calculations in conjunction with Green’s function techniques. It was found that the quantum conductance was very sensitive to structural deformation and relaxation. The conductance decreased monotonically, with increasing strain, for both compression and elongation. In an elongated tube, strain-induced electron localization was the predominant mechanism that controlled the contribution of molecular orbitals to conductance. Transport properties were also sharply affected by the presence of defects. The results demonstrated that the electronic transport properties of a nanoscale device were closely related to the nature of the band structure of the metallic lead, the details of chemical bonding in the scattering region and the interaction between Bloch states and molecular orbitals.

Effects of Strain and Defects on the Electron Conductance of Metallic Carbon Nanotubes. Y.He, C.Zhang, C.Cao, H.P.Cheng: Physical Review B, 2007, 75[23], 235429