Domain suppression in the negative differential conductivity region of carbon nanotubes by applied ac electric field

Abstract

We study theoretically the electron transport properties in achiral carbon nanotubes under the influence of an external electric field E(t) using Boltzmann’s transport equation to derive the current-density. A negative differential conductivity (NDC) is predicted in quasi-static approximation i.e., ωτ << 1, similar to that observed in superlattice. However, a strong enhancement in the current density intensity is observed in NDC of the achiral carbon nanotubes. This is observed at where the constant electric field E0 is equal to the amplitude of the AC electric field E1. The peak of the NDC intensity occurs at very weaker fields than that of superlattice under the same conditions. The peak intensity decreases and shifts to right with the increase in the amplitude of the ac field. This mechanism suppresses the domain formation and therefore could be used in terahertz frequency generation