Electric field effect on the anisotropic optical properties of elliptical nanotubes

Abstract

The energy spectrum and wave functions of an electron in elliptical nanotubes with hard walls under the influence of an electric field directed along the major or minor axis of the ellipse were studied within the framework of the effective mass approximation using the finite element method. The considered nanotubes have equal thickness along the major and minor axes. The dependence of energy levels and oscillator strengths on the nanotube ellipticity and the strength of the external electric field was calculated. It was shown that the selection rules for quantum transitions of an electron depend on the nanotube ellipticity, the magnitude and direction of the electric field, and the orientation of the linear polarisation of the electromagnetic wave. It has been shown that the selection rules for quantum transitions of an electron depend on the nanotube ellipticity, the magnitude and direction of the electric field, as well as the orientation of the linear polarisation of the electromagnetic wave. Conditions under which the probability of electron quantum transitions to high-energy excited states increases have been determined. The obtained results are also applicable to the corresponding elliptical nanorings and can be useful for designing optoelectronic devices with specified energy and polarisation properties.