Mutual rectification of alternating currents induced by electromagnetic waves in graphene

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.     

Mutual rectification of alternating currents in graphene

Induction of direct current in graphene by a pair of electromagnetic waves with different frequencies and mutually perpendicular polarization planes affecting its surface is described by solving the quantum kinetic equation. It is shown that the major contribution to the constant component of the current comes from inelastic scattering of charge carriers.     

Influence of a magnetic field on the mutual rectification of alternating currents induced by electromagnetic waves in graphene

The direct component of the electric current induced in graphene placed in a constant magnetic field has been found in the case where two electromagnetic waves with two mutually perpendicular planes of polarization are normally incident on the surface of the sample. It has been demonstrated that the direct component of the current along the direction of the electric field vector of the wave with the frequency ω₁ arises only when the ratio between the frequencies of the incident waves is ω₁/ω₂ = 2 or 1/2. In the latter case, the direct current component appears only in the presence of a magnetic field.     

Mutual rectification of cnoidal and sinusoidal electromagnetic waves in a superlattice

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.     

Effect of the mutual rectification of two electromagnetic waves with perpendicular polarization planes in a superlattice based on graphene

The effect of the mutual rectification of two electromagnetic waves with perpendicular polarization planes in a superlattice based on graphene was investigated. It was shown that, due to the nonadditive nature of the electronic spectrum of a superlattice based on grapheme, a constant term of current arises along its axes. The dependence of the constant of current density on the intensity of an electromagnetic wave is oscillatory in nature.     

Mutual rectification of cnoidal and sinusoidal electromagnetic waves with orthogonal polarization planes in a graphene-based superlattice

The effect of mutual rectification of two electromagnetic waves in a graphene superlattice is studied for a cnoidal wave polarized along the superlattice axis and a sinusoidal wave polarized along the orthogonal direction. An expression for the density of the direct current generated by mixing of these waves is obtained. The direct current is studied as a function of the cnoidal wave amplitude. The possibility of varying both the value and the direction of the direct current with varying the cnoidal wave amplitude is shown.     

On the radiation of fermions in the field of two electromagnetic waves

We consider the radiation of an electron with anomalous magnetic moment in the field of two plane electromagnetic waves of different frequencies but the same direction of propagation. We obtain formulas for the probability amplitude and intensity of photon emission by the electron in the field of these waves. The possibility of photon emission by a neutral fermion in such a field is shown.Translated from Izvestiya Vysshikh Uchebnykh Zavedenii Fizika, No. 11, pp. 55–60, November, 1972.The authors would like to than Professor V. G. Bagrov for his attention to this work.     

Absorption of electromagnetic waves by graphene

The power of the circularly polarized electromagnetic wave absorbed by graphene is calculated using the Boltzmann kinetic equation written in the relaxation approximation and the numerical Monte Carlo simulation. It is shown that in the limit of large radiation amplitudes the power absorbed by graphene is directly proportional to the amplitude irrespective of the electron gas statistics.     

Electron in the field of two plane electromagnetic waves and an inhomogeneous electric field

This work examines the motion of an electron in an electromagnetic field consisting of the field of two plane electromagnetic waves of different frequencies ₁, ₂ and an electric fieldE'=(E₀ + E₃cos₃)e₃. The method of separation of variables is used to construct the solution of the Hamilton-Jacobi equation. The motion of the electron in the external electromagnetic field is described by those solutions of the Dirac equation coinciding with the eigenfunctions of the commutating operators.Translated from Izvestiya Vysshikh Uchebnykh Zavedenii, Fizika, No. 2, pp. 89–94, February, 1982.     

Amplification of electromagnetic pulses in graphene with Hubbard interaction by a uniform high-frequency alternating field

The Maxwell equations for an electromagnetic field propagating in graphene in which electrons with different spin projections experience a strong Coulomb repulsion at a single node are considered. An effective equation analogous to the classical (1+1)-dimensional sine-Gordon equation is derived. Electrons are treated within the framework of the quantum formalism with allowance for changes in the dispersion law in the presence of Coulomb interaction. The effective equation is solved numerically, and the effect of Coulomb repulsion is identified. The amplification of an ultrashort pulse is observed when an external uniform electromagnetic field with a period shorter than the pulse duration is applied.     

Spatial rectification of the electric field of space charge waves

A new phenomenon associated with a nonlinear interaction of optically excited space charge waves has been discovered in photorefractive crystals of the sillenite family. This interaction provides a spatial rectification of the electric field of the space charge waves and leads to a temporally oscillating, but spatially homogeneous electric field of the order of 50-60 V/cm which is detected by a probe beam via the electro-optic effect. Taking into account that the displacement current plays an important role, we demonstrate a very good agreement between the experimental data and the suggested theoretical model.     

Radiation of a scalar particle in the field of two oppositely directed electromagnetic travelling waves

The radiation of a charged spinless particle in a field of two linearly polarized, oppositely directed electromagnetic travelling waves is treated in the small-field approximation. Equations are derived for the radiation probability, and the polarization properties of the radiation are studied.Translated from Izvestiya Vysshikh Uchebnykh Zavedenii Fizika, Vol. 12, No. 1, pp. 69–73, January, 1969.The authors thank Professor I. M. Ternov for interest in this study and useful discussions.     

Dynamics of interacting qubits in a strong alternating electromagnetic field

The populations of energy levels of interacting qubits have been studied as functions of the field amplitude and other control parameters for a constant frequency of the external electromagnetic field. It has been found that the qubit coupling constant strongly affects the quantum-coherent Landau-Zener transitions between the qubit states and the formation of an interference pattern in level populations, depending on the field parameters. It has been demonstrated that it is possible to determine the qubit coupling constant by Landau-Zener interferometry.     

Induced radiation by fermions in the field of two collinear plane electromagnetic waves of arbitrary polarization

In the present article we consider the effect of induced radiation of fermions, moving in the field of two monochromatic plane waves of arbitrary polarization, propagating in one direction. Equations are obtained for the radiation probability and total radiated power of a particle. The spin behavior in this process is investigated.Translated from Izvestiya Vysshikh Uchebnykh Zavedenii, Fizika, No. 11, pp. 12–18, November, 1974.     

Induced radiation of fermi particles with anomalous magnetic moment in the field of two electromagnetic waves

The induced radiation of an electron with anomalous magnetic moment in the field of two electromagnetic waves is investigated. Formulas for the probability and the total power of radiation are derived. The spin effects are investigated. The possibility of induced radiation of a neutral Fermi particle in the same field is demonstrated.Translated from Izvestiya Vysshikh Uchebnykh Zavedenii Fizika, No. 11, pp. 71–76, November, 1972.The authors thank Professor V. G. Bagrov for attention to the work.     

Instability of plasma waves in an electromagnetic field

Summary In the presence of a weak laser field the plasma scattering by electrons is discussed.

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Riassunto In presenza di un campo laser debole, si discute la diffusione del plasma mediante elettroni.

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Резюме В присутствии слабого лазерного поля обсуждается рассеяние плазмы на электронах.

     

Effect of transverse entrainment of charge carriers by the field of two electromagnetic waves in a semiconductor

The effect of transverse entrainment of charge carriers by two electromagnetic waves propagating in mutually perpendicular directions in a semiconductor with a parabolic dispersion law has been investigated. The dc component of the electric current density that appears in the direction perpendicular to the wave vectors has been calculated in the constant relaxation time approximation. It has been shown that the transverse dc current vanishes at a particular phase difference of the incident waves determined by the relaxation time of charge carriers in the material.