Transport properties of a potassium-doped single-wall carbon nanotube rope

Four-probe resistance vs temperature and gate voltage are reported for an individual single-wall carbon nanotube rope before and after doping in situ with potassium. All the features in $R(T)$ from unoriented bulk material, before and after doping, are qualitatively reproduced by the rope data. The 5.3 K conductance of the pristine rope decreases with positive gate voltage, while G vs Vg becomes featureless after K doping.