Gate-Voltage Dependence of Zero-Bias Anomalies in Multiwall Carbon Nanotubes

The gate-voltage dependence of zero-bias anomalies (ZBA) in vanadium (V)/multiwall carbon nanotube (MWNT)/V structure was analyzed. It was shown that as temperature is reduced, the conductance decreases with a functional form consistent with a power law. It was found that the exponent depends significantly on gate voltage and this exponent dependence cannot be explained by Luttinger-liquid (LL) theory for ballistic MWNTs. The obtained results were interpreted within the framework of the nonconventional Coulomb blockade theory for strongly disordered MWNTs.