Single-walled Carbon Nanotubes Ionization Energy Of Carbon Atoms Adsorbed With The Magnetic Moment Of Quantum Computing

Carbon nanotubes (CNTs) are new materials with nanometer diameter. The nanotubes can be viewed as seamless hollow tubular structures being constructed from a single rolled sheet of graphite, and have large length/diameter ratio. So they are considered as quasi-one dimensional nanomaterials. Due to their special structures with mechanical and electronic properties, nanotubes will have vast and promising prospects of application in many fields, such as nanoelectronic devices, materials science, etc.Many people have investigated structural defects of carbon nanotubes, and their influences on the properties of carbon tubes. One of the most common defects to be created is the carbon vacancy-adatom pair. So it's important to study the influence of this kind of defect on the electronic structure of surface. P.O.Lehtinen etc. used to consider this defect when they were studying an adatom on a graphene sheet and on carbon nanotubes. However, in their researches they only considered armchair and zigzag carbon nanotubes. We here use first principle method based on the density-function theory to calculate adsorption energy and magnetic moment of some carbon nanotubes that have Chirality. The results imply that the biggest absorption energy for the condition of perpendicular to the axis does not appear on the "bridgelike" structure's midpoint, but slightly away midpoints, when an adatom on carbon nanotubes with Chirality. However, this phenomena is not observed in the condition of parallel to the axis. And the absorption energy for the condition of perpendicular to the axis is larger than that of parallel to the axis. The adatom is spin polarized for both conditions, but the magnitude of magnetic moment depends mainly on the electric structure of tubes. The electromagnetics' properties of nanotubes with same Chirality but different radius mainly change along the radial of the tubes. Finally, we have studied the ionization potential of tubes. We find that formula of ionization potential derived from CSD model can not be applied to carbon nanotubes. Ionization energy of tubes oscillate with the increase of diameter of carbon tube. As a whole, the trend is approaching to the ionization energy of graphene with the increase of the radius. From this result, we can estimate that the primary factor, which decides the ionization energy of the tubes, is not the size of the tubes. The essential factor is electronical structure.