Interaction of ultrashort light pulses with carbon nanotubes

The possibility of existence of electromagnetic solitons in carbon nanotubes is investigated on the basis of the coupled equations for the classical distribution function of electrons in such nanotubes and the Maxwell equations for electromagnetic fields. Solitons arise due to the matched change in the classical distribution function and the electric field formed by nonequilibrium electrons of a carbon nanotube. The data of numerical calculations, indicative of the existence of solitons, are reported.     

Dynamics and damping of electromagnetic solitons in the carbon nanotube bundles

The possible existence of the electromagnetic solitons in carbon nanotubes is analyzed. Solitons appear as a result of a simultaneous change in the classical electron distribution function and the electric field produced by the nonequilibrium electrons in carbon nanotube. The effective equations are obtained for the dynamics of electromagnetic field with allowance for the interband transitions causing soliton damping. The numerical results are presented evidencing the existence of solitons in carbon nanotubes. The propagation dynamics is studied for the periodic electromagnetic waves in the bundles of carbon nanotubes. The shape of electromagnetic wave is found to change during its propagation.     

Periodic current domains in a system of carbon nanotubes

The dynamics of propagation of periodic electromagnetic waves and the current induced by them in a system of carbon nanotubes is investigated. The study is performed on the basis of the analysis of the coupled equations for the classical distribution function of electrons in carbon nanotubes and the Maxwell equations for an electromagnetic field. An effective equation describing the electromagnetic field dynamics is obtained. Periodic changes in the form of an electromagnetic wave during its propagation are revealed. This effect is related to the energy exchange between periodic vibrations with different periods in the system under consideration. The corresponding regions of the current through carbon nanotubes form a regular periodic domain structure. The results of numerical calculations are reported, which make it possible to consider this effect at different problem parameters.     

Periodic current domains in bundles of carbon nanotubes

The dynamics of propagation of periodic electromagnetic waves and the related electric current in bundles of carbon nanotubes is studied. The study is based on an analysis of coupled equations for the classical electron distribution function in carbon nanotubes and the Maxwell equations for an electromagnetic field. An effective equation is obtained to describe the electromagnetic-field dynamics. Periodic changes are revealed in the shape of the electromagnetic wave propagating in a carbon medium. This effect is considered to be related to energy exchange between periodic oscillations having different periods. Certain regions of the current passing through carbon nanotubes form a periodic domain structure. The results of numerical calculations allow this effect to be analyzed as a function of the problem parameters.     

Ultrashort Optical Pulses in Carbon Nanotubes and Heavy-Ion Absorption

Propagation of electromagnetic waves in a medium with zigzag carbon nanotubes is studied. Based on the Maxwell equations, an effective equation for the electromagnetic field vector potential is derived, which takes into account ion oscillations in the dielectric medium with nanotubes. It is found that the pulse shape depends on the character of oscillations of heavy ions, which may absorb the electromagnetic field, and on other parameters of the problem.     

Dissipative solitons in carbon nanotubes

The possibility of analogs of dissipative solitons occurring in arrays of carbon nanotubes under the action of a high-frequency external uniform electric field on the array has been established theoretically. The electromagnetic field has been considered in terms of the Maxwell equations, and the conduction electrons in carbon nanotubes have been described by the Boltzmann kinetic equation in the relaxation-time approximation. The external ac electric field serves for energy pumping of the electronic subsystem, whereas a finite relaxation time leads to energy dissipation. The generation of a periodic sequence of electromagnetic pulses has been revealed. This sequence can be used for producing terahertz frequencies.     

Electromagnetic solitons in carbon nanotubes at low temperatures

The propagation of a variable electromagnetic field in arrays of “zigzag” carbon nanotubes at low temperatures is considered. The electronic system of carbon nanotubes is analyzed using the Hamilton formalism with ignoring interactions with the phonon subsystem because the electromagnetic field pulse is extremely short. An effective equation for the amplitude of the electromagnetic field vector-potential was obtained. Solutions-analogues of solitons were revealed; these solutions corresponded to solitons for the cosine electronic subsystem dispersion law. The dependences of the nonlinear solutions obtained on problem parameters were analyzed.     

Interaction of two-dimensional electromagnetic breathers in an array of carbon nanotubes

The propagation and interaction of two-dimensional bipolar electromagnetic pulses in an array of semiconducting carbon nanotubes have been investigated. The electromagnetic field in the array of carbon nanotubes has been described by the Maxwell’s equations reduced to the non-one-dimensional wave equation. The initial distribution of the field has been specified in the form of approaching breathers bounded by a Gaussian profile in the plane perpendicular to the pulse propagation direction. The numerical solution of the wave equation has revealed the possibility of stable propagation of breathers in the array of carbon nanotubes. It has been found that the interaction of electromagnetic breathers in the array of semiconducting carbon nanotubes has a character of quasi-elastic collisions.     

A Two-Dimensional Extremely Short Optical Pulse in a System of Carbon Nanotubes in a Direct Current Electric Field

The effect of an external dc electric field on the two-dimensional extremely short optical pulse propagating in a zigzag carbon nanotube array was investigated. The electromagnetic field evolution in the investigated nanotube system is described by the Maxwell equations. Using numerical simulation, the interaction between the pulse electromagnetic field and the external electric field applied to the carbon nanotube array is analyzed.     

Collision of extremely short optical pulses in semiconductor carbon nanotubes

The interaction of extremely short optical pulses in semiconductor carbon nanotubes is discussed. An equation is derived for the dynamics of the electromagnetic field in a system of semiconductor carbon nanotubes at low temperatures, whose solutions are analogs to the solitons of the sine-Gordon equation. The behavior of extremely short optical pulses in semiconductor carbon nanotubes on collision is analyzed.     

Electromagnetic vortices in an array of carbon nanotubes

The dynamics of electromagnetic vortices in an array of carbon nanotubes is investigated. The electromagnetic field is described by Maxwell (two-dimensional wave) equations. Calculation modeling is performed. The resulting mass center velocity of the vortices is zero, and the intensity distribution its field changes periodically over time.     

Dynamics of a two-dimensional light bullet propagating in a system of carbon nanotubes with a velocity greater than the speed of light in the medium

The behavior of a two-dimensional light bullet propagating with a velocity greater than the speed of light in a medium consisting of semiconducting carbon nanotubes is investigated by means of numerical simulation. The electromagnetic field of the investigated system is described using Maxwell’s equations with allowance for the electric and magnetic properties of the carbon nanotubes and the medium in which they are embedded.     

Dust acoustic wave oscillations in metallic carbon nanotubes

We present theoretical analysis of plasmon dispersion in single-walled metallic carbon nanotubes (SWCNTs) in the presence of low-frequency electromagnetic radiation, based on classical electrodynamic formulations and linearized hydrodynamic model. We assume that metallic carbon nanotubes (CNTs) are charged due to the field emission, and hence the metallic nanotubes can be regarded as charged dust rods surrounded by degenerate electrons and ions. Calculations are performed for the transverse electric (TE) and transverse magnetic (TM) waves, respectively, by solving the Maxwell and hydrodynamic equations with appropriate boundary conditions.     

Polarized electromagnetic solitons in carbon nanotubes

The alternating electromagnetic field of general polarization spreading in the zigzag carbon nanotube system was studied in the case of low temperatures. The electron system of carbon nanotubes was described microscopically, omitting the interaction with the phonon system due to the extremely short pulse of the electromagnetic field. An effective equation was derived for the amplitudes of the electromagnetic field vector potential.     

Theoretical study of armchair single-walled carbon nanotubes in the presence of a strong laser field: high harmonic generation

The nonlinear optical response of armchair single-walled carbon nanotubes under high-intensity laser irradiation is investigated theoretically and numerically because the generation of high harmonics requires a strong laser field and come from the nonlinear motion of π electrons in carbon nanotubes. A nonperturbative approach is performed to investigate the effect of group velocity on the high harmonics spectrum by nanotubes. A set of the quantum kinetic equations is derived, which includes coupled equations for the density matrix. By solving the density matrix and the current density equations numerically, we have studied the high-order harmonic generation from metallic carbon nanotubes driven by an electromagnetic external field.     

Extremely short two-dimensional optical pulses in an array of carbon nanotubes in the presence of a constant electric field

The interaction between the electromagnetic fields of extremely short two-dimensional optical pulses propagating in an array of zigzag-type carbon nanotubes and an external constant electric field is investigated. The evolution of the investigated system’s electromagnetic field is described by Maxwell’s equations.     

Electronic properties of multi-defected zigzag carbon nanotubes

Electronic properties of multi-defected zigzag single-walled carbon nanotubes are investigated by use of the tight-binding Green's function method. The Stone-Wales defects and the vacancies are considered. We find that the conductance sensitively depends on the realistic defect configurations for the metallic zigzag carbon nanotubes. Interestingly, the electronic transport properties of the nanotubes with three vacancies can be considered as the sum effect of two double-vacancies, while those with Stone-Wal...     

Ultimately short optical pulses in carbon nanotubes in dispersive nonmagnetic dielectric media

We consider Maxwell’s equations for an electromagnetic field propagating in carbon nanotubes placed in dispersive nonmagnetic dielectric media. An effective equation having the form of an analog of the classical sine-Gordon equation was obtained and analyzed numerically. The dependence of the pulse on the type of carbon nanotubes, initial pulse amplitude, and dispersion constants of the medium was revealed.     

Dissipative solitons in carbon nanotubes

The theoretical possibility of the existence of dissipative solitons in an array of carbon nanotubes when they are subjected to external uniform high-frequency electric field is discussed. An external alternating field is used for energy pumping of the electron subsystem, while a finite relaxation time leads to energy dissipation. The generation of a periodic sequence of electromagnetic pulses is revealed.