Suppression of the unconventional metallic behavior by gate voltage in MWNT device

We observed an ambipolar behavior in multiwalled carbon nanotubes (MWNT) in a back-gate configuration, which allowed us to perform systematic inspection of the low-temperature transport properties against gate voltage. Power-law behaviors in temperature and bias-dependent conductance, disappeared when a high gate voltage was applied, and conductance became temperature- and bias independent. This indicates a gate-induced transformation from the unconventional to the normal metallic states in MWNT.