The effective mass approximation is used to consider plasma and magnetoplasma waves in an electron system on the surface of the semiconductor cylindrical nanotube. The electron-electron coupling is taken into account in the random phase approach. In the case of a degenerate electron gas the spectral windows on the wavevector-frequency plane and the spectra of the waves are obtained. Their frequencies undergo quantum oscillations of the de Haas-van Alfven type which are attributed to the Fermi level traversing the sub-zone boundaries in the electron energy spectrum. The spectrum and the damping of waves in the non-degenerate electron gas were found. In a magnetic field parallel to the cylinder axis the frequencies of the magnetoplasma waves sustain the Aharonov-Bohm type oscillations that appear with changing magnetic field strength.

Adsorption of transition-metal atoms on boron nitride nanotube: A density-functional study

The influence of isolated impurity atoms on the electron energy spectrum in a parabolic quantum dot in quantizing magnetic field is studied. The impurity potential is approximated by a Gaussian separable operator which allows one to obtain the exact solution of the problem. We demonstrate that in the electron energy spectrum there is a set of local levels which are split from the Landau zone boundaries in the upward or downward direction depending on the impurity type. We have calculated the local level positions, the wave functions of electrons in bound states, and the residues of the electron scattering amplitudes by impurity atoms at the poles. PACS:73.21.La, 71.70.Di, 71.55.-i Keywords: impurity atoms, quantum dots, impurity states, local levels, residues of the electron scattering amplitudes Physicists and technologists are interested in quantum dots [1] for a number of reasons, the main one of which is that they are functional elements of modern devices and electronic gadgets. This interest has intensified since experimentalists learnt how to synthesize these nanosystems in laboratories. For theorists, quantum dots are of interest because they are convenient objects to test new calculation methods. Of particular interest are properties of the quantum dots with impurity atoms in a magnetic field. Due to a small number of electrons in the quantum dot even a single impurity atom influences strongly its properties. Within a limited volume of the quantum dot in a magnetic field, interesting phenomena become present like hybridization of spatial and magnetic quantization of the electron's motion. The electron localization on individual impurity atoms considered here is one of such phenomena.The impurities in bulk-and nanosystems play a double role. On the one hand, they determine the low-temperature behaviour of the kinetic characteristics of a system. On the other hand, the impurities influence the energy spectrum of the system thereby leading to the appearance of local and resonant levels in the energy spectrum of quasi-particles [2][3][4]. These levels exert a profound influence on the properties of solids [2][3][4][5][6][7][8][9].In this work, we present the results of a theoretical study made on the local states of electrons in quantum dots in a quantizing magnetic field using the method of degenerate regular perturbations [2]. We shall use the model of a parabolic quantum dot [1] based on 2D electron gas with the confinement potential

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