Dynamics of optically injected currents in carbon nanotubes

TL;DR

This paper theoretically investigates how optically injected currents in carbon nanotubes evolve over time, focusing on Coulomb forces and resulting dipole radiation in the THz range, revealing dynamics distinct from plasma oscillations.

Contribution

It introduces a theoretical model for the dynamics of optically injected currents in carbon nanotubes, emphasizing nonuniform Coulomb forces and dipole radiation generation.

Findings

Dipole radiation in the THz frequency range is produced.

Strong nonuniform Coulomb forces dominate carrier dynamics.

Different regimes of current evolution are characterized.

Abstract

We consider theoretically the dynamics of electric currents optically injected in carbon nanotubes. Although the plasma oscillations are not seen in these systems, the main effect on the carrier's motion is due to strongly nonuniform space-charge Coulomb forces produced by time-dependent separation of injected electron and hole densities. We calculate evolution of the dipole moment characterizing the time- and coordinate-dependent charge density distributions and analyze different regimes of the dynamics. The developed time-dependent dipole moment leads to a dipole radiation in the THz frequency range for typical parameters of injected currents.