Suppression of Macroscopic Quantum Effects in Arrays with Spiral Nanotubes Associated with the Dispersion of Their Characteristic Sizes.

The interest in studying the optical and electrical properties of nanotubes is caused by their specific features, such as the band gap, which is dependent on the nanotube structure symmetry, and high electrical conductivity, due to which they can be considered as promising materials for nanoelectronics. Most existing methods of preparation of these structures suggest the formation of nanotubes in the form of arrays, with a large dispersion of their characteristic sizes. Therefore, the most important problem is to analyze the influence of size dispersion on the optical properties of a nanotube bundle. The purpose of this study is to theoretically investigate the influence of dispersion of the spiral-nanotube radius on macroscopic quantum effects arising at anisotropic transfer of the photon momentum to the electron subsystem. The model under consideration is a cylindrical nanotube with infinitely thin walls. The nanotube spiral symmetry is described by extended spiral perturbation simulated by the δ potential. The emf of photon drag and emf arising due to Joule heating of the electron system are calculated in the quadrupole approximation with allowance for the dispersion of nanotube radii. The influence of dispersion of the characteristic spiral-nanotube sizes on macroscopic quantum effects in a longitudinal magnetic field is theoretically studied. Analytical formulas are derived (with allowance for the dispersion of the characteristic sizes of spiral nanotubes in an array) for the photon-drag emf in a standing electromagnetic wave and for the emf due to Joule heating of the electron system by the photon-drag current of electrons through a nanotube in a longitudinal magnetic field. The influence of the dispersion of characteristic sizes of spiral nanotubes in an array on the macroscopic quantum effects is investigated. It is shown that the macroscopic quantum effect, which is related to the photon-drag emf in a standing electromagnetic wave, may be suppressed in real arrays of nanotubes, where the dispersion of their radii plays a significant role. It is also shown that suppression of the emf, related to Joule heating of the electron system by the photon-drag current through a nanotube, increases with an increase in the standard deviation, which is due to significant dispersion of the characteristic spiral-nanotube radii. [ABSTRACT FROM AUTHOR]