Temperature dependence of the conductance of multiwalled carbon nanotubes

We report on the conductance of multiwalled carbon nanotubes as a function of voltage and temperature between room temperature and 4.2 K. The data show a monotonic decrease in conductance as the temperature is lowered. At temperatures below about 20 K, a nonlinearity develops in the $V(I)$ data, corresponding to a pronounced dip in the conductance near zero bias. The size of the dip increases as the temperature is lowered. The data are explained in terms of transport through a Luttinger liquid. The measured conductance contains contributions from the nanotube-contact interface and from the nanotube itself.