Total energy of charged carbon nanotubes and single-electron tunneling

In this paper, two analytical formulas are derived from density-functional-theory calculations: the highest occupied molecular orbital energy and the total energy of a charged single-walled carbon nanotube (SWNT) as functions of the charge. These formulas are used to examine the electron tunneling of a SWNT acting as a quantum dot. The final results validate the usual semi-classical approach, but some intermediate results are different. The capacitance of a SWNT is also discussed, since the formulas are expressed in terms of this quantity. Finally, a prototype of single-electron transistor is suggested.