Modeling of current-voltage and dl/dV-characteristics of nanocontact “Niobium — Carbon nanotube (5, 5) — Niobium”

Abstract

The paper investigated the current-voltage and dI/dV-characteristics of nanocontact “Niobium — Carbon nanotube (5,5) — Niobium” using the program Atomistix ToolKit with Virtual NanoLab. At computer simulation of transport characteristics of nanocontact the method of nonequilibrium Green's functions and the local density approximation were used. The current-voltage characteristics, the differential conductivity, transmittance spectra and the spectral density of the reporting nanocontact current for different values of the bias voltage and temperature were calculated. The nature of electron transport through the reporting nanocontact shows that despite the small relationship between the size of the contact and coherence length, such systems at low temperatures behave like Josephson structures. This makes it possible to conclude about decreasing the size of the superconducting electron pairs (Cooper pairs) in low-dimensional systems, where the correlation between the electrons due to the absence of a periodic structure on the surface of the system is due to phonon transmitted through its volume. In these contacts at a low temperature there is a coincidence of the transmission spectra at different values of the bias voltage. The results may be useful for the simulation electrical properties of nanocontacts and the elements of nanoelectronics.