Author(s)

Sulemana S. Abukari, Samuel Y. Mensah, Kofi W. Adu, Natalia G. Mensah, Kwadwo A. Dompreh, Anthony Twum, Chales L. Y. Amuah, Matthew Amekpewu, Musah Rabiu

Department of Applied Physics, University for Development Studies, Navorongo, Ghana.
Department of Physics, Laser and Fibre Optics Centre, University of Cape Coast, Cape Coast, Ghana.
Department of Physics, The Pennsylvania State University, Altoona, USA; Materials Research Institute, The Pennsylvania State University, University Park, USA.
National Centre for Mathematical Sciences, Ghana Atomic Energy Commission, Accra, Ghana; Department of Mathematics, University of Cape Coast, Cape Coast, Ghana.

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.

Carbon Nanotubes; Negative Differential Conductivity and Generation of Terahertz Radiation

S. Abukari, S. Mensah, K. Adu, N. Mensah, K. Dompreh, A. Twum, C. Amuah, M. Amekpewu and M. Rabiu, "Domain Suppression in the Negative Differential Conductivity Region of Carbon Nanotubes by Applied AC Electric Field," World Journal of Condensed Matter Physics, Vol. 2 No. 4, 2012, pp. 274-277. doi: 10.4236/wjcmp.2012.24045.