Spontaneous Decay of Excited Atomic States near a Carbon Nanotube

The spontaneous decay process of an excited atom placed inside or outside a carbon nanotube is analyzed. Calculations have been performed for various achiral nanotubes. The effect of the nanotube surface is shown to increase the atomic spontaneous decay rate by up to 6 orders of magnitude compared with that of the same atom in vacuum. This increase is associated with nonradiative decay via surface excitations in the nanotube.

Figure 1

Factor $\xi ({\omega }_A)$ calculated from Eq. (6) for the atom in the center of different zigzag CNs. Surface axial conductivities ${\sigma }_{zz}$ appearing in Eq. (6) were calculated in the $\tau$ approximation with $\tau =3\times {10}^{-12}\mathrm{s}$ (see Ref. 6).

Figure 2

Factor $\xi ({\omega }_A)$ for the atom at different distances outside zigzag (9,0) CN. Inset: $\xi ({\omega }_A)$ at ${\omega }_A=3{\gamma }_0/\hslash$ as a function of $r_A/R_{cn}$ for the atom near (9,0) CN in the model of the ideally conducting cylinder.

Figure 3

Ratio ${\Gamma }_r/\Gamma$ calculated from Eq. (7) for the atom in the center of different zigzag CNs.