O. E. Glukhova, A. S. Kolesnikova, I. S. Nefedov, I. N. Saliy, M. M. Slepchenkov, G. V. Savostiano

Creation of a miniature source of terahertz radiation based on the low-dimensional structures is one of the urgent problems of modern applied physics. The interest to the terahertz frequency band is caused by broad prospects of its possible applications in fundamental research and practical applications. In particular, due to radiation in the terahertz band one can carry out identification of the molecule in its chemical composition, to obtain three-dimensional image of the object at high resolution, to perform the scanning of luggage on the transport and search of explosives in their spectral composition. In this context, the aim of this work is the development of the radiating element in the terahertz range. We have considered the fullerene C60 as a radiating element, oscillating under the influence of an electric field inside the potential well created by the van der Waals interaction between the polymerized C60 fullerenes and free charged fullerene inside the nanotube. The object of the study is the structure, being the nanotube with a diameter of 1,39 nm and a length of 6,16 nm. This tube has one opened end and a chain of three fullerenes connected by chemical bonds with each other and with the wall of the nanotube is placed near the other end. Inside the nanotube, one charged fullerene is located near the chain of fullerenes. This charged fullerene is not connected by chemical bonds with other fullerenes. The motion of a charged fullerene inside the nanotube is described by the molecular dynamics method with regard to the radiation force and electrostatic field force , where m - the mass of each atom of the free fullerene; r - radius vector of each atom of the free fullerene; F - the interatomic interaction force; F0 - the radiation force; Fe = q E; E - an external electric field; q - the electronic charge density. During the study, the conditions ensuring the oscillatory motion of a charged fullerene were revealed. In our model a charged fullerene is the radiating element. It was proposed to place the fullerene in a potential well of van-der-Waals interactions between the charged fullerene and a chain of three uncharged fullerenes. This potential well has an irregular shape due to deformation of the tube, caused by its interaction with the C60 chain. Put in a potential well fullerene under an external electric field starts to oscillate (progressive-returnable movement) with a certain frequency radiation. This frequency is calculated by the time of fullerene movement from one wall of the potential well to the other. As a result of calculations, it was found that the fullerene having a charge of +3e under the electric field with strength of 106 V/cm does undamped oscillation with the frequency of 0,36 THz during 50-80 ps.