D. V. Zav’yalov

Volgograd State Pedagogical University, Zarizyn, Volgograd, Russia

Are you D. V. Zav’yalov?

Claim your profile

Publications (25)18.07 Total impact

  • S. V. Kryuchkov, E. I. Kukhar, D. V. Zav’yalov
    [show abstract] [hide abstract]
    ABSTRACT: d'Alembert equation written for the electromagnetic waves propagating in the graphene superlattice is discussed. The chaotic behavior of the electrons in graphene superlattice is studied by the Melnikov method. Dynamic chaos of electron in graphene superlattice is shown to appear for certain intervals of amplitudes of preset alternate current. The frequency dependence of the critical amplitude of alternate current above which would be a chaos is investigated.
    Physica E Low-dimensional Systems and Nanostructures 02/2014; · 1.52 Impact Factor
  • S.V. Kryuchkov, E.I. Kukhar, D.V. Zav’yalov
    [show abstract] [hide abstract]
    ABSTRACT: The components of the conductivity tensor of graphene placed in a constant magnetic field that oriented transversely the graphene layer are calculated. The calculation is performed on the basis of the Boltzmann equation, written in the relaxation time approximation. The method for the numerical determination of the relaxation time taking into account the electron–phonon interaction explicitly is offered. The dependences of the relaxation time on the magnetic field intensity and on the temperature are found with this method.
    Physica E Low-dimensional Systems and Nanostructures 09/2013; 53:124–129. · 1.52 Impact Factor
  • S V Kryuchkov, E I Kukhar’, D V Zav’yalov
    [show abstract] [hide abstract]
    ABSTRACT: The semiclassical theory of the dynamics of the charge carriers in graphene and in graphene superlattices exposed to a high-frequency electric field is developed. The dispersion law of the solid averaged over the period of the high-frequency electric field is found with the Kapitza method. The band gap in graphene is shown to arise under a high-frequency electric field polarized circularly. The effective mass of charge carriers in the center of the Brillouin band of the graphene superlattice is found to change sign under certain values of the amplitude of the high-frequency field. These values are shown to determine the bounds of the regions of the electromagnetic 2π-pulse stability. The dynamics of the π-pulse in a graphene superlattice is studied.
    Laser Physics 04/2013; 23(6):065902. · 2.55 Impact Factor
  • D. V. Zav’yalov, S. V. Kryuchkov
    [show abstract] [hide abstract]
    ABSTRACT: The current flowing along a cylindrical quantum wire with a superlattice in the case of the simultaneous application of dc and ac fields is calculated. It is assumed that the wire contains impurity centers, whose ionization results in the generation of nonequilibrium carriers in the conduction band. It is found that the dependence of the steady component of the current on the ac-field frequency is a step-like function. It is shown that the distance between steps depends on the conduction miniband width and the transverse quantum confinement parameters and is independent of the impurity-level depth.
    Semiconductors 09/2008; 42(10):1204-1207. · 0.60 Impact Factor
  • D. V. Zav’yalov, S. V. Kryuchkov, E. V. Marchuk
    [show abstract] [hide abstract]
    ABSTRACT: The current-voltage characteristic of a material with a narrow conduction band in a strong electric field is studied taking into account ionization of deeply lying impurities in the model, in which collisions of charge carriers are described in the Fokker-Planck approximation. The results are compared with analogous results obtained in the v approximation. It is shown that the results obtained earlier in the v approximation coincide with our results to within ∼ 5%. It is noted that the Fokker-Planck model additionally provides the temperature dependence of the current-voltage characteristic.
    Technical Physics 01/2008; 53(9):1243-1246. · 0.55 Impact Factor
  • D. V. Zav’yalov, S. V. Kryuchkov, E. I. Kukhar
    [show abstract] [hide abstract]
    ABSTRACT: The conductivity of a semiconductor superlattice in a magnetic field perpendicular to the superlattice axis is calculated. The dependence of the conductivity on the magnetic field strength is studied. It is found that there is a magnetic-field range where the resistivity is proportional to the magnetic field strength.
    Physics of the Solid State 01/2007; 49(8):1554-1557. · 0.77 Impact Factor
  • D. V. Zav’yalov, S. V. Kryuchkov, E. I. Kukhar
    [show abstract] [hide abstract]
    ABSTRACT: Drag of charge carriers in a superlattice subjected to a constant axially oriented electric field by an electromagnetic wave also propagating along the axis is considered. The drag-current density is calculated and its dependence on the constant-field strength E1 and the electromagnetic-wave intensity I is analyzed. Reversals of the current direction are found to occur for certain values of E1 and I.
    Semiconductors 01/2007; 41(6):704-707. · 0.60 Impact Factor
  • O. P. Volosnikova, D. V. Zav’yalov, S. V. Kryuchkov
    [show abstract] [hide abstract]
    ABSTRACT: New properties are predicted for a helical quantum wire (HQW) that must be manifested under the action of a constant electric field that produces a kind of quantization of the electron energy spectrum. As a result, the spectrum acquires a miniband structure inherent in quantum superlattices. The high-frequency properties of an HQW are studied. A threshold dependence of the high-frequency conductivity of the HQW on the strength of the applied constant electric field is established.
    Technical Physics Letters 08/2006; 32(9):785-787. · 0.56 Impact Factor
  • D. V. Zav’yalov, S. V. Kryuchkov, E. I. Kukhar
    [show abstract] [hide abstract]
    ABSTRACT: Mutual rectification of two electromagnetic waves, one of which is a weak sinusoidal wave and the other of which is a cnoidal wave, is considered. An expression for the constant component of the density of a current arising in a superlattice in the presence of these waves is obtained. The dependence of the constant component of the current density on the amplitude of the cnoidal wave is analyzed. The case where the sinusoidal wave frequency is twice as large as the cnoidal wave frequency is considered in detail.
    Optics and Spectroscopy 01/2006; 100(6):916-919. · 0.56 Impact Factor
  • [show abstract] [hide abstract]
    ABSTRACT: The effect of a quantizing static electric field parallel to the axis of a semiconductor superstructure on the charge-carrier mobility in the direction perpendicular to this axis is studied. The transverse conductivity of charge carriers was calculated on the basis of a quantum-mechanical kinetic equation. Using the results of the numerical analysis, the dependences of the time of the carriers’ momentum relaxation on their transverse energy and also the dependences of the charge-carrier mobility on the strength of the longitudinal quantizing electric field were plotted. It is shown that the dependence of the density of current flowing perpendicularly to the superlattice axis on the strength of the longitudinal electric field is oscillatory.
    Semiconductors 01/2006; 40(12):1429-1431. · 0.60 Impact Factor
  • D. V. Zav’yalov, S. V. Kryuchkov, E. I. Kukhar’
    [show abstract] [hide abstract]
    ABSTRACT: The transverse magnetoconductivity has been calculated for a one-dimensional semiconductor superlattice under the action of an external quantizing electric field. The dependence of the conductivity on the electric and magnetic fields is analyzed and found to exhibit a strongly pronounced resonance character. The maximum values of conductivity are evaluated.
    Technical Physics Letters 01/2005; 31(9):722-724. · 0.56 Impact Factor
  • [show abstract] [hide abstract]
    ABSTRACT: The conductivity of a quantum cylinder with a parabolic lateral confinement potential and a superstructure is studied under conditions where uniform static quantizing electric and magnetic fields are applied along the cylinder axis. The charge carriers are assumed to be scattered by optical phonons. The dependence of the current density along the superlattice axis on the dc magnetic field is obtained. It is shown that, under certain conditions, the so-called Stark-hybrid-phonon resonance appears due to the hybridization of the electronic energy spectrum. In turn, this gives rise to a sharply nonmonotonic magnetic-field dependence of the current density.
    Physics of the Solid State 01/2005; 47(6):1169-1171. · 0.77 Impact Factor
  • [show abstract] [hide abstract]
    ABSTRACT: The current density in a combination of a 2D electron gas and a superlattice subjected to a strong electric field under exposure to a cnoidal electromagnetic wave is studied, with electron-phonon coupling explicitly taken into account. A dc electric quantizing field is directed along the superstructure axis, with the vector of the field strength of the nonlinear wave being perpendicular to this axis. It is found that the constant component of the current density along the superlattice axis is oscillatory and depends on the electric field strength.
    Semiconductors 01/2005; 39(2):198-201. · 0.60 Impact Factor
  • [show abstract] [hide abstract]
    ABSTRACT: The intraminiband absorption of a nonlinear electromagnetic wave is investigated taking into account the fact that impurity absorption occurs simultaneously. The impurity absorption leads to an increase in the concentration of charge carriers in the conduction miniband, which, in turn, changes the shape of the electromagnetic wave. Thus, this problem is self-consistent. The dependences of the intraminiband absorption coefficient of a cnoidal electromagnetic wave on the electric field strength of the wave taking into account the ionization processes and disregarding them are found numerically. It is shown that taking into account the ionization processes leads to the expansion of the strong absorption region to higher fields.
    Optics and Spectroscopy 12/2004; 98(1):20-24. · 0.56 Impact Factor
  • D. V. Zav’yalov, S. V. Kryuchkov
    [show abstract] [hide abstract]
    ABSTRACT: The longitudinal magnetothermo-emf of a one-dimensional semiconductor superlattice has been studied in the quasi-classical limit (τ−1 ≪ Ω ≪ μ, where τ is the charge carrier relaxation time, Ω is the cyclotron frequency, and μ is the chemical potential). It is established that oscillations caused by the Landau quantization are modulated by oscillations related to a finite width of the conduction band. Conditions under which such a modulation is especially clearly manifested are determined.
    Technical Physics Letters 01/2004; 30(5):435-437. · 0.56 Impact Factor
  • [show abstract] [hide abstract]
    ABSTRACT: Absorption of cnoidal electromagnetic waves, which are the most general periodic solution to the sine-Gordon equation, by electrons of a one-dimensional quantum semiconductor superlattice in the process of impurity ionization is studied in terms of the semiclassical approximation. The dependence of the absorption coefficient on the electric field of an electromagnetic wave is found to be nonmonotone with a pronounced peak.
    Optics and Spectroscopy 01/2004; 96(1):63-65. · 0.56 Impact Factor
  • D. V. Zav’yalov, S. V. Kryuchkov
    [show abstract] [hide abstract]
    ABSTRACT: The influence exerted by a nonlinear electromagnetic wave on the dc conductivity of a superlattice is analyzed. An essentially nonlinear current-voltage (I-V) characteristic is obtained. A portion of negative absolute conductivity appears in the I-V characteristic at certain nonlinear-wave parameters. A distinction is made between the given case and that of a monochromatic wave, when a large number of such portions may exist. For typical superlattice parameters, some of the negative absolute conductivity must appear at a nonlinear wave field strength E 0≈1.8103 V/cm.
    Semiconductors 01/2001; 35(5):554-556. · 0.60 Impact Factor
  • D. V. Zav’yalov, S. V. Kryuchkov
    [show abstract] [hide abstract]
    ABSTRACT: Intraminiband absorption of light by electrons in a quantum superlattice in a quantizing electric field is investigated theoretically taking into account the electron-phonon interaction. It is assumed that the interaction with optical dispersion-free phonons makes the main contribution to electron scattering. It is shown that the point ω=ω 0 (ω is the light frequency, and ω 0 is the optical phonon frequency) conditionally divides the ω dependence of the absorption into two parts: ω<ω 0, the region of exponentially weak absorption and ω>ω 0, the region of “strong” absorption. An electric field shifts the region of strong absorption in the red direction of the spectrum.
    Semiconductors 10/1999; 33(11):1225-1228. · 0.60 Impact Factor
  • D. V. Zav’yalov, V. I. Konchenkov, S. V. Kryuchkov
    [show abstract] [hide abstract]
    ABSTRACT: The problem concerning the mutual influence of two electromagnetic waves of different frequencies with the electric field vectors directed perpendicularly to each other on the charge carriers in graphene on a SiC substrate has been solved. The possibility of generating a direct component in the electric current has been analyzed. It has been shown that the direct current is generated only in the case where the ratio between the frequencies of incident waves is equal to 2. Dependences of the current on the phase shift between the incident waves and on the temperature have been obtained.
    Physics of the Solid State 51(10):2157-2160. · 0.77 Impact Factor
  • D. V. Zav’yalov, V. I. Konchenkov, S. V. Kryuchkov
    [show abstract] [hide abstract]
    ABSTRACT: The possibility of cyclotron echo generation in graphene on a silicon carbide substrate has been predicted on the basis of the direct quasi-classical Monte Carlo simulation. The nature of this effect is the quasi-relativistic dependence of the effective mass of charge carriers on their velocity. The numerical values of the field strengths at which the effect should be most pronounced are found.
    Physics of Wave Phenomena 19(4). · 0.19 Impact Factor