Effect of magnetic field on quantum state energies of an electron confined in the core of a double walled carbon nanotube

In this paper we report the effect of external magnetic field and core radius on the excited quantum state energies of an electron confined in the core of a double walled carbon nanotube. The goal is accomplished by using Wentzel–Kramers–Brillioun (WKB) approximation method within the effective mass approximation and confinement potential. All numerical analysis were carried out in a strong confinement regime. The results show that the electron energy increases with the increase in external magnetic field at a given core radii. The electron energy is also found to increase as the core radius of the CNT decreases and for core radius a>5nm the energy becomes almost zero. The effect of magnetic field on the excited state energies of the confined electron is more evident for smaller core radius a<1 nm. The observed results are important for calculations of spin polarized current in carbon nanotube quantum dot devices [1].