Effective mass of an electron in an electromagnetic field

The effective-mass formalism is shown capable to describe the fully relativistic motion of an electron in a strong, locally plane, electromagnetic wave, determining the drift caused by the wave inhomogeneity and by additional weaker fields. The limits of this approach are discussed, in connection with the occurrence of resonances.     

Spin effects during electron motion in an axially symmetric electromagnetic field

The spin properties of an electron due to quantization of its motion in a focusing electromagnetic field are studied. Within the framework of the complex Maslov WKB method, an explicit dependence is obtained for the quasiclassical particle energy spectrum on the spin. It is shown that for electrons in an axial channeling regime this will result in a different degree of states' stability depending on the value of the projection of the spin on the moment of rotation.Translated from Izvestiya Vysshikh Uchebnykh Zavedenii, Fizika, No. 9, pp. 91–96, September, 1990.     

Influence of quantum fluctuations on the motion of an electron in the field of a plane electromagnetic wave

The influence of radiation on the change in the energy, the longitudinal component of the momentum, and the shape of the orbit of an electron in the field of a wave is investigated. A comparison with the analogous quantities in the limiting case of high strength of a high-frequency electromagnetic field is made.Translated from Izvestiya Vysshikh Uchebnykh Zavedenii, Fizika, No. 2, pp. 95–97, February, 1991.     

Reduction and second quantisation of generalised electromagnetic field for zero mass system

Reduction and second quantisation of generalised electromagnetic fields in the presence of massless spin-1/2 particles carrying both electric and magnetic charges have been carried out in terms of Lomont-Moses realisation of irreducible representations of Poincare group and the expression for field Hamiltonian has been derived.     

Effects on planetary motion of an external electromagnetic field

By considering an uncharged mass embedded in an external electromagnetic field we show that the Einstein corrections to the Newtonian results may further be modified.     

Effect of zero point motion on the hyperfine field at an interstitial positive muon site in ferromagnetic Ni

Using the inhomogeneous electron charge and spin density distribution around the octahedral site in ferromagnetic nickel from a self-consistent band structure scheme, and the abiabatic approximation, we have calculated the muon hyperfine field as a function of the muon displacement. By folding the electron spin density at the vibrating muon site obtained in a self-consistent Kohn-Sham scheme with the finite width of the muon wave function, we find a striking effect on the average muon hyperfine field. The result agrees better with the experiment than earlier calculations based on the jellium model.     

Charged particle motion in an electromagnetic field on Kerr background geometry

In this paper we study the trajectories of charged particles in an electromagnetic field superimposed on the Kerr background. The electromagnetic fields considered are of two types: (i) a dipole magnetic field with an associated quadrupole electric field, (ii) a uniform magnetic field. The contribution of the background geometry to the electromagnetic field is taken through the solutions of Petterson and Wald respectively. The effective potential is studied in detail for ther-motion of the particles in the equatorial plane and the orbits are obtained. The most interesting aspect of the study is the illustration of the effect of inertial frame dragging due to the rotation of the central star. This appears through the existence of nongyrating bound orbits at and inside the ergo surface. The presence of the magnetic field seems to increase the range of stable orbits, as was found in a previous study involving the Schwarzschild background.     

Three-dimensional Gross-Neveu model at nonzero temperature and in the presence of an external electromagnetic field

The phase structure of the (2+1)-dimensional Gross-Neveu model is considered at a nonzero temperatureT and in the presence of an external electromagnetic field. The major results are as follows: 1. AtT=0,H0 (a magnetic field), the original symmetry of the model breaks for anyH values. 2. AtT=0,E0 (an electric field) anE _c is shown to exist, such that forEE _c the original symmetry is broken, but forE>E _c the vacuum of the model is symmetric. 3. AtT0,H0, and at a fixedT value such anH _c (T) is shown to exist that forH>H _c (T) the chiral invariance of the model is spontancously broken. For any fixedH value there exists such anT _c (H) that forT>T _c (H) the symmetry restores. The phase portrait of the model is drawn.     

Green's function of an electron in an external electromagnetic field

New field-theoretical representations are obtained for Green's function of an electron in an external electromagnetic field, making it possible to simplify its calculation substantially.Translated from Izvestiya Vysshikh Uchebnykh Zavedenii, Fizika, No. 2, pp. 33–37, February, 1982.     

Anomaly of the temperature dependence in an electron gas system

A re-evaluation is given of the temperature dependent term in the first order exchange contribution to the grand partition function for an electron gas. The existence and origin of the logarithmic term in the temperature-dependent part are shown in a very simple manner.     

Spin polarization and temperature dependence of electron effective mass in quantum wires

The electron effective mass in GaAs quantum wires has been estimated by using a full dynamical random-phase approximation to examine its properties versus spin polarization, temperature, and carrier density. A decrease of mass with spin polarization is seen. The minority mass increases with the polarization while the majority mass decreases and this behaviour is seen for all densities. A maximal enhancement of mass at moderate temperature around 25 K is also presented. These calculations show a qualitative consistence with results in two-dimensional systems and help to control the electronic transport in quantum wires.     

Spontaneous emission by an electron in an arbitrary plane-wave electromagnetic field

On the basis of general expressions obtained for the total emission probability and the probability of a radiation transition with spin reversal of an electron moving in an arbitrary plane-wave electromagnetic field, the particular case of a plane-wave field is considered. It is shown that under certain conditions self-polarization of the electron spin is possible during the emission by an electron in a field which is the superposition of a constant crossed field and a plane, elliptically polarized, electromagnetic wave.Translated from Izvestiya Vysshikh Uchebnykh Zavedenii, Fizika, No. 10, pp. 93–98, October, 1982.     

An approximate method for the investigation of the Potts antiferromagnet in zero external field at zero temperature

We calculate the exact ground state degeneracy for the antiferromagnetic q-state Potts model in zero external field at zero temperature for two and three coupled chains. On the basis of these exact results the ground state degeneracy of the square lattice is expressed as an explicit function of q which is found to be a good approximation.     

Electric field dependence of carrier temperature in semiconductors in the warm electron range

The electric field dependence of carrier temperature in semiconductors in the warm electron range is theoretically studied for the case of an intermediate carrier concentration where the distribution function of the carriers is Maxwellian with an elevated carrier temperature and the momentum loss process is governed predominantly by scattering with optical phonons.     

Integrals of the motion for an electron in a quantized plane electromagnetic wave

The structure of the integrals of motion of an electron moving in a plane quantized electromagnetic wave is discussed, using the general solution of the integrals of motion of a system whose Hamiltonian is a quadratic form of creation and annihilation operators with constant coefficients.Translated from Izvestiya Vysshikh Uchebnykh Zavedenii, Fizika, No. 2, pp. 116–121, February, 1977.     

Does the electromagnetic mass of an electron depend on where it is?

The question of whether the electromagnetic mass of the electron depends upon its electromagnetic environment is discussed in connection with previous theoretical and experimental work. When the quantization of the field in other than free space is properly understood, it is evident that the true electromagnetic mass of the electron is unaltered.     

The nonextensive parameter for nonequilibrium electron gas in an electromagnetic field

The nonextensive parameter for nonequilibrium electron gas of the plasma in an electromagnetic field is studied. We exactly obtained an expression of the q$q$-parameter based on Boltzmann kinetic theories for plasmas, where Coulombian interactions and Lorentz forces play dominant roles. We show that the q$q$-parameter different from unity is related by an equation to temperature gradient, electric field strength, magnetic induction as well as overall bulk velocity of the gas. The effect of the magnetic field on the q$q$-parameter depends on the overall bulk velocity. Thus the q$q$-parameter for the electron gas in an electromagnetic field represents the nonequilibrium nature or nonisothermal configurations of the plasma with electromagnetic interactions.     

Beta decay in the field of an electromagnetic wave and experiments on measuring the neutrino mass

Investigations of the effect of an electromagnetic wave field on the beta-decay process are used to analyze the tritium-decay experimental data on the neutrino mass. It is shown that the electromagnetic wave can distort the beta spectrum, shifting the end point to the higher energy region. This phenomenon is purely classical and it is associated with the electron acceleration in the radiation field. Since strong magnetic fields exist in setups for precise measurement of the neutrino mass, the indicated field can appear owing to the synchrotron radiation mechanism. The phenomenon under consideration can explain the experimentally observed anomalies in the spectrum of the decay electrons; in particular, the effect of the “negative square of the neutrino mass.”