Free oscillations of magnetic fluid in strong magnetic field

The paper presents the esults of measuring the elastic parameters of an oscillatory system (coefficient of pondermotive elasticity, damping factor, and oscillation frequency) whose viscous inertial element is represented by a magnetic fluid confined in a tube by magnetic levitation in a strong magnetic field. The role of elasticity is played by the pondermotive force acting on thin layers at the upper and lower ends of the fluid column. It is shown that, by measuring the elastic oscillation frequencies of the magnetic fluid column, it is possible to develop a fundamentally new absolute method for determining the saturation magnetization of a magnetic colloid.     

Sodium in a strong magnetic field

We investigate the effects of a magnetic field with low to intermediate strength on several spectroscopic properties of the sodium atom. A model potential is used to describe the core of sodium, reducing the study of the system to an effective one-particle problem. All states with principal quantum numbers n = 3, 4, 5, 6 and 7 are studied and analysed. A grid of twenty values for the field strength in the complete regime B = 0 - 0.02 a.u. is employed. Ionisation energies, transition wavelengths and their dipole oscillator strengths are presented. Received 5 November 2002 Published online 4 February 2003     

Resonance double magnetic bremsstrahlung in a strong magnetic field

The possibility of resonance double magnetic bremsstrahlung in the approximation of weakly excited electron states in a strong external magnetic field is analyzed. The differential probability of this process in the Breit-Wigner form is obtained. The probability of double magnetic bremsstrahlung (second-order process of perturbation theory) is compared with the probability of magnetic bremsstrahlung (first-order process of perturbation theory).     

Phonon-plasmon modes in a strong magnetic field

Frequencies of phonon-plasmon coupled modes in a strong magnetic field were calculated. The calculations were performed in the long-wave approximation with regard to the electron damping and intrinsic lifetime of optical phonons. The dependence of the Raman scattering cross section on the carrier concentration and the magnetic field intensity was calculated.     

Photon dispersion in a strong magnetic field

In an external magnetic field analytical properties are studied of the photon polarization tensor calculated as the electron-positron loop in the Furry picture. The polarization tensor is reexpressed as a sum over singular contributions coming from e⁺e^?-pair photocreation in semidiscrete Landau states. The solutions of the photon dispersion equation (i.e., the one for the poles of the photon propagator) are described. The shape of the photon dispersion curve obtained is responsible for the effect of photon deflection by a strong magnetic field. No physically reliable solutions, apart from spurions, are found for the longitudinal photon mode. An infinite number of solutions with complex space-momentum are found, with no apparnet ghosts among them. An attempt is made to interprete the former in terms of possible bound and quasibound states of electron and positron pairs.     

Mesoscopics in a strong perpendicular magnetic field

Properties of the diffusive motion in a strong magnetic field are discussed. We describe two possible phase memory breaking mechanisms. We present a high magnetic field form of the discussion propagator which can be used to describe the conductance fluctuations of a two-dimensional electron gas in the regime of well developed Shubnikov-de Haas oscillations.     

Interacting electron gas in a strong magnetic field

The density response function of an electron gas in a strong magnetic field shows logarithmic singularities due to scattering across the Fermi surface. We analyze the parquet equations for the vertex function in leading logarithmic order for a general interaction potential. The parquet equations are solved for a special interaction potential (Schulz and Keiter model). The divergence of the density response function at extremely high fields is discussed in connection with a possible transition to a Wigner lattice.     

On quark matter in a strong magnetic field

The effect of strong magnetic field on the bulk properties of quark matter is reinvestigated takingu, d ands-quarks as well as electrons in the presence of magnetic field. Here the bag pressure is chosen such that in the absence of magnetic field and at zero temperature the binding energy of theuds-system is <930 MeV while that ofud-system is greater than 940 MeV. It is observed that the equation of state changes significantly in a strong magnetic field. At finite temperature the electron chemical potential varies between 6 and 50 MeV. Thus the expansion of thermodynamical quantities in powers ofT/(Μ _i ² -M _v ⁽ⁱ⁾² )^1/2 is valid only up to few MeV. For high temperatures ∼40 MeV the exact integral expressions are to be taken.     

Neutrino pair creation in a strong magnetic field

An expression for the probability of neutrino pair creation by an electron in an ultrastrong magnetic field is obtained. The calculations are done using the exact solutions of the Dirac equation in a magnetic field in the low energy approximation of the Weinberg-Salam model.Translated from Izvestiya Vysshikh Uchebnykh Zavedenii, Fizika, No. 9, pp. 39–41, September, 1982.     

Low-lying exciton levels in a strong magnetic field

The behavior of the n = 2 and n = 3 exciton levels in a strong magnetic field is analyzed for the case in which the spacing between the Coulomb levels is much greater than that between Landau levels. The results are compared with experimental data on magnetooptical absorption in Cu₂O. The observed splitting of these levels can be attributed to the appearance of a Landau series above the Coulomb levels.Translated from Izvestiya VUZ. Fizika, No. 2, pp. 7–11, February, 1970.     

Dynamic magnetic susceptibility of a two-layer film in a strong magnetic field

A theoretical study is reported of the effect of interlayer exchange coupling on the resonance properties of a two-layer magnetic film with “easy-axis” and “easy-plane” anisotropic layers in a strong tilted magnetic field. The dependence of the resonance fields on the tilting angle of the external magnetic field to the film has been obtained, the tensor of integrated high-frequency film susceptibility has been found, and its dependence on the strength and orientation of the external field, as well as on layer thickness, has been analyzed. The results obtained agree with the available experimental data.     

Repeated Compton scattering in a strong magnetic field

Science China Physics, Mechanics & Astronomy - Repeated scatterings of unpolarized photons by non-relativistic electrons in a static and uniform magnetic field are investigated by using the...     

Two-dimensional quantum antiferromagnet in a strong magnetic field

The behaviour of the two-dimensional quantum antiferromagnet of arbitrary spin in a strong transversal magnetic field on a square lattice is studied in terms of the equivalent Bose gas problem. The existence of phase transition from the state characterized by “quasi-long-range” magnetic order to the disordered ferromagnetic state is demonstrated. The expressions for correlation functions, thermodynamical and magnetic characteristics are derived.     

Pion decay constants in a strong magnetic field

Decay constants of the charged and neutral pions in magnetic field are considered in the framework of the effective quark-antiquark lagrangian respecting Gell-Mann–Oakes–Renner (GOR) relations at zero field. The \(\sqrt {\frac{{{e_q}B}}{\sigma }} \) dependence is found in strong fields e_qB ? σ for the neutral pion, while the charged pion constant decreases as \(\sqrt {\frac{\sigma }{{{e_q}B}}} \).     

Cold dense hydrogen in a strong magnetic field

The equation of state of a hydrogen plasma in a magnetic field that is quantizing for charged fermions is obtained within the framework of the statistical thermodynamics of systems in equilibrium for a model of extremely degenerate, ideal Fermi gases. Values of the mass density corresponding to nonrelativistic and relativistic electrons are considered, as well as densities exceeding the threshold for neutronization of cold, magnetized, electron-proton matter. Brest State University. Translated from Izvestiya Vysshikh Uchebnykh Zavedenii, Fizika, No. 10, pp. 57–59, October, 1997.