Metallic single-walled carbon nanotubes have been proposed to be good one-dimensional conductors. However, the finite curvature of the graphene sheet that forms the nanotubes and the broken symmetry due to the local environment may modify their electronic properties. We used low-temperature atomically resolved scanning tunneling microscopy to investigate zigzag and armchair nanotubes, both thou...

The total version of geometric–arithmetic (GA) index of graphs is introduced based on the end-vertex degrees of edges of their total graphs. In this paper, the total GA index is computed for zigzag polyhex nanotubes by using some results on GA index and mentioned nanotubes. Also, we compute the edge GA index for the subdivision graphs of TUC C (R) and TUAC [p',q'] nanotubes. 4 8 6

We have investigated the electronic structure and carrier mobility of armchair and zigzag single-walled MoS₂ nanotubes using density functional theory combined with Boltzmann transport method with relaxation time approximation. It is shown that armchair nanotubes are indirect bandgap semiconductors, while zigzag nanotubes are direct ones. The band gaps of single-walled MoS₂ nanotubes are along ...

Single-wall carbon nanotubes provide ideal model one-dimensional (1-D) condensed matter systems in which to address fundamental questions in many-body physics, while, at the same time, they are leading candidates for building blocks in nanoscale optoelectronic circuits. Much attention has been recently paid to their optical properties, arising from 1-D excitons and phonons, which have been reve...

We investigate the band-gap modiication by collapsing deformation in C, BN, and BC3 nanotubes through rst-principles pseudopotential calculations. Semiconductor-metal transitions occur when zigzag C and armchair BC3 nanotubes undergo collapsing deformation, while in zigzag BN tubes, a variation of band gaps from 5 to 2 eV is found. On the other hand, the band gaps of armchair BN and zigzag BC3 ...

The effect of defect complexes on the stability, structural and electronic properties of single-walled carbon nanotubes and boron nitride nanotubes is investigated using the ab initio pseudopotential density functional method implemented in the Castep code. We found more substantial atomic relaxations in the zig-zag carbon nanotube than the armchair one. We find that the B(C)B(c) defect introdu...

Single-walled boron nitride nanotubes are chosen as model reactants, and (10,0) and (6,6) are chosen as representatives of armchair and zigzag nanotubes, respectively, to study the interaction of carbenes of the type :CX2. It is found that, contrary to the case of carbon nanotubes, boron nitride tubes, particularly armchair BNNTs, do not show a propensity for cyclopropane ring formation. The SW...