  The phenomenon of superconductivity depends on the coherence of the phase of
the superconducting order parameter. The resistive transition in
quasi-one-dimensional (quasi-1D) superconductors is broad because of a large
phase fluctuation. We show that the resistive transition of a superconducting
single-walled carbon nanotube bundle is in quantitative agreement with the
Langer-Ambegaokar-McCumber-Halperin (LAMH) theory. We also demonstrate that the
resistive transition below T^*_c = 0.89T_c0 is simply proportional to exp
[-(3\beta T^*_c/T)(1-T/T^*_c)^3/2], where the barrier height has the same form
as that predicted by the LAMH theory and T_c0 is the mean field superconducting
transition temperature.
