Broken Symmetry, Boundary Conditions, and Band Gap Oscillations in Finite Single Wall Nanotubes
نویسندگان
چکیده
We have shown that the interplay between the broken symmetry of finite single-wall nanotubes (SWNT) and the boundary conditions affects the electronic properties of SWNTs in a profound way. For finite SWNTs (p, q) characterized by p = k+l, q = k−l, p−q = 2l, l = 0, 1, · · · , k, and k = 1, 2, · · ·, we found that the band gaps of finite SWNTs belonging to a certain k exhibit similar well-defined oscillating patterns but with diminishing amplitudes from the armchair (l = 0) to the zigzag (l = k) SWNTs. These profound changes hold intriguing implications in the potential utilization of these finite NTs as the basic component of molecular scale devices. Typeset using REVTEX
منابع مشابه
Broken symmetry, boundary conditions, and band-gap oscillations in finite single-wall carbon nanotubes
The interplay between the broken symmetry and the boundary conditions alters profoundly the electronic properties of carbon single-wall nanotubes ~SWNTs! of finite-lengths. For SWNTs (p ,q) characterized by p 5k1l , q5k2l , 0<l<k , and k51,2, . . . , the energy gaps for finite SWNTs belonging to a given family k exhibit strikingly similar oscillating patterns for even NT sections, but the gap m...
متن کاملStructure and electronic properties of single–walled zigzag BN and B3C2N3 nanotubes using first-principles methods
The structure and the electronic properties of single-walled zigzag BN and B3C2N3 nanotubes (n, 0; n=4–10) were investigated using first-principles calculations based on a density functional theory. A plane–wave basis set with periodic boundary conditions in conjunction with Vanderbilt ultrasoft pseudo-potential was employed. The energy gap of ZB3C<su...
متن کاملStructure and electronic properties of single–walled zigzag BN and B3C2N3 nanotubes using first-principles methods
The structure and the electronic properties of single-walled zigzag BN and B3C2N3 nanotubes (n, 0; n=4–10) were investigated using first-principles calculations based on a density functional theory. A plane–wave basis set with periodic boundary conditions in conjunction with Vanderbilt ultrasoft pseudo-potential was employed. The energy gap of ZB3C<su...
متن کاملSymmetry of boundary conditions of the Dirac equation for electrons in carbon nanotubes
We consider the effective mass model of spinless electrons in single wall carbon nanotubes that is equivalent to the Dirac equation for massless fermions. Within this framework we derive all possible energy independent hard wall boundary conditions that are applicable to metallic tubes. The boundary conditions are classified in terms of their symmetry properties and we demonstrate that the use ...
متن کاملThermoelectric Power of Single-Walled Carbon Nanotubes
We have measured the temperature-dependent thermoelectric power (TEP) of crystalline ropes of single-walled carbon nanotubes. The TEP is large and holelike at high temperatures and approaches zero as T ! 0. The results argue against the opening of a gap at low temperature in these materials. When derived from a simple band structure picture, the TEP of a single metallic nanotube is significantl...
متن کامل