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1.
S. Yu. Glazov N. E. Mescherkova 《Bulletin of the Russian Academy of Sciences: Physics》2011,75(12):1613-1615
The conductivity of a superlattice based on graphene in an alternating electric field with a vector of intensity directed
along the axis of the superlattice is described. The electronic system is described in terms of the kinetic Boltzmann equation
in approximation of a constant time of relaxation. Nonlinear responses to the applied harmonic field are calculated and analyzed. 相似文献
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S. Yu. Glazov A. A. Kovalev N. E. Mescheryakova 《Bulletin of the Russian Academy of Sciences: Physics》2012,76(12):1323-1325
The law of plasma wave dispersion in an electron gas in a superlattice based on graphene on a striped substrate is studied numerically. Calculations are performed based on the quantum theory of plasma waves in the approximation of random phases with allowance for umklapp processes. The estimated plasmon frequencies for the graphene-based superlattices on striped substrates now under theoretical study is ω ≤ 1014 s?1. 相似文献
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Harmonics generation of high-frequency radiation in a plasma embedded in a constant electric field is investigated theoretically. It is shown that the electron directed motion due to the static electric field yields the appearance in the plasma emission spectrum of high-frequency radiation even harmonics. The conditions are established when the even harmonics generation is as effective as that of the odd ones. At variance with the odd harmonics, the even harmonics polarization plane is found to rotate with respect to that of the fundamental field. The basic dependencies concerning the rotation angle and the generation efficiency on the plasma and field parameters are established.Received: 3 May 2004, Published online: 14 September 2004PACS:
52.50.Jm Plasma production and heating by laser beams (laser-foil, laser-cluster, etc.) - 52.38.Dx Laser light absorption in plasmas (collisional, parametric, etc.) 相似文献
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J. H. Block 《固体与材料科学评论》1976,6(2):133-156
Since the invention of the field ion microscope (FIM) by E. W. Muller1 and the first mass-spectrometric analysis of field ions by Inghram and Gomer,2 these tools for field ionization have been developed considerably, as described in several monographs and summarizing artilces.3–8 Field ion mass spectrometry (FIMS) can analyze solid surfaces with extreme sensitivity. The experimental facilities enable ultimately the identification of single surface particles, which can be correlated to individual surface sites within the atomic scale of a surface. The atom-probe, which was developed by E. W. Müller,9 can now analyze surface particles with high precision in mass resolution. 相似文献
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The effect of a transverse dc electric field on two-wave mutual rectification in a graphene superlattice (GSL) is investigated. Two field orientations are considered: (i) the polarization plane is parallel to the GSL axis and (ii) the polarization plane is perpendicular to the GSL axis. In both cases, the constant field is perpendicular to the polarization plane. The current density is calculated within a one-miniband model using the Boltzmann equation in the approximation of constant relaxation time. 相似文献
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E. I. Kukhar’ S. V. Kryuchkov E. S. Ionkina 《Bulletin of the Russian Academy of Sciences: Physics》2017,81(1):47-50
Longitudinal and transverse high-frequency conductivities of a graphene superlattice placed in an additional dc electric field are calculated. It is shown that in a sufficiently strong transverse field, the dependence of the longitudinal high-frequency conductivity of the superlattice on the ac field frequency changes. This effect is explained by the nonadditivity of the electronic spectrum of the investigated structure. 相似文献
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《Superlattices and Microstructures》1995,17(1):97-105
We present variational calculations of excitonic states in a superlattice coupled with a wide quantum well in electric fields. The electronic states in the structure are analyzed by using both exact solutions of the one-dimensional Schrödinger equation and the simple tight-binding approximation. We demonstrate the latter method to be well applicable to calculating and designing complicated irregular superlattices. The electron spectrum can be conveniently interpreted as a result of field-induced mixing and anticrossing of electron quantized states in the enlarged quantum well with non-equidistant Stark-ladder states in the semi-infinite ideal superlattice. The electron-hole Coulomb attraction results in a relative redistribution between the extended and the localized states in the exciton. The allowance for this redistribution has a particularly strong influence upon the exciton oscillator strength and radiative lifetime. 相似文献
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The maintenance of resonance between a particle and a nonuniform, circularly polarized wave in a vacuum by a longitudinal
electrostatic field is analyzed on the basis of the concept of an autoresonance regime as the motion of a charged particle
along the autoresonance separatrix; the possibility in principle of autoresonance motion of a particle in a space with nonzero
curvature is established: the conditions for autoresonance in a strong static gravitational field are obtained and discussed.
Taganrog State Radio-Engineering University. Translated from Izvestiya Vysshikh Uchebnykh Zavedenii, Fizika, No. 2, pp. 29–34,
February, 1997. 相似文献
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The representation of the tunneling conductance G(T) of the “dirty” (with low concentrations of the same nonmagnetic impurities in the I layer) N–I–N junction (where N is a normal metal and I is an insulator) in the form of a sum of conductances of random quantum jumpers penetrating the disordered I layer is obtained in the low-temperature region. It is shown that the axis of the parameter δ = |ε0 ? εF| giving the deviation of the energy of ε0 the quasi-local electron state on the impurity in the I layer from the Fermi energy of εF the dirty N–I–N junction contains a series of bifurcation points, at the transition through each of which (in the direction of the increase in δ) the number of maxima on the temperature dependence G(T) increases by unity; i.e., a new maximum is “born” on the curve G(T). Numerical estimates are given for the characteristic parameters of dirty N–I–N junctions indicating the possibility of the experimental observation of at least the first of these maxima. 相似文献
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We briefly review recent theoretical and simulation studies of charged colloidal dispersions in alternating electric fields (AC fields). The response of single colloid to an external field can be characterized by a complex polarizability, which describes the dielectric properties of the colloid and its surrounding electrical double layer. We present computer simulation studies of single spherical colloid, using a coarse-grained mesoscale approach that accounts in full for hydrodynamic and electrostatic interactions as well as for thermal fluctuations. We investigate systematically a number of controlling parameters, such as the amplitude and frequency of the AC-fields. The results are in good agreement with recent theoretical predictions. 相似文献
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The stabilization of partially-premixed jet flames in the presence of high potential electric fields
Numerous research efforts have focused on flame stabilization and emissions. Based on initial experiments, specific mechanisms resulting from DC electric fields were chosen to be investigated, namely the chemical, thermal, and ionization mechanisms. Numerical simulations were performed on premixed propane-ozone-air flames to characterize ozone effects on flame speed resulting from the formation of ozone in high potential electric fields. These results were compared against partially premixed flame experiments to observe the dominant influences within leading edge stabilization within high potential electric fields. It was found that the electromagnetic or ionization influences, serve as the dominant effect on the combustion zone. 相似文献
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Yee Yee Oo K.N. Nagendra G. Ramachandran 《Journal of Quantitative Spectroscopy & Radiative Transfer》2007,108(2):161-179
The polarization of radiation by scattering on an atom embedded in combined external quadrupole electric and uniform magnetic fields is studied theoretically. Limiting cases of scattering under Zeeman effect, and Hanle effect in weak magnetic fields are discussed. The theory is general enough to handle scattering in intermediate magnetic fields (Hanle-Zeeman effect) and for arbitrary orientation of magnetic field. The quadrupolar electric field produces asymmetric line shifts, and causes interesting level-crossing phenomena either in the absence of an ambient magnetic field, or in its presence. It is shown that the quadrupolar electric field produces an additional depolarization in the Q/I profiles and rotation of the plane of polarization in the U/I profile over and above that arising from magnetic field itself. This characteristic may have a diagnostic potential to detect steady-state and time-varying electric fields that surround radiating atoms in solar atmospheric layers. 相似文献
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In the paper the electric field induced reorientation of a nematic liquid crystal film is investigated theoretically and experimentally. Both alternating and static fields are considered. 相似文献
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M. Wołoszyn B. J. Spisak 《The European Physical Journal B - Condensed Matter and Complex Systems》2012,85(1):10
We report the effect of substitution of Cr by V and Mn in the
spin-
\frac12\frac{1}{2}
1
2
dimer
compound Sr3Cr2O8. In the pentavalent Cr site, V ion has
zero effective moment, while Mn remains in the spin-1 state. For both V and Mn
substitutions, the gap in the spin excitation spectra remains almost unchanged in the
dilute doping regime. The low temperature Curie tail, expected to be originated from free
or quasi-free magnetic ions, is found to be larger in case of V doped samples. However,
inter-dimer interaction is found to be stronger in the Mn doped samples. The underlying
magnetic behaviour of these doped samples is presumably related to the effect of broken
dimers due to random substitutions. 相似文献