Observation of a Logarithmic Temperature Dependence of Thermoelectric Power on Multiwall Carbon Nanotubes

We have investigated the thermoelectric power (TEP) of millimeter-long aligned multiwall carbon nanotubes down to a temperature of $T$=1.5 K, and observed for the first time an accurate $T\mathrm{l}\mathrm{n}T$ dependence at low temperatures. This behavior is possibly originated from the repulsive interaction between the electrons in a disordered local environment.