Temperature and Magnetic Field Dependencies in a Model of Diamagnetic Hysteresis in Beryllium

The model of diamagnetic hysteresis loop of strongly correlated electron gas at the conditions of dHvA effect is developed. It is shown, that in the framework of Rayleigh theory for magnetization loop, the coercive force and remnant magnetization in every period of dHvA oscillations are characterized by strong dependencies on temperature, magnetic field and Dingle temperature.Comment: 7 pages, 4 figure

Diamagnetic Phase Transition and Phase Diagrams in Beryllium

The model of diamagnetic phase transition in beryllium which takes into account the quasi 2-dimensional shape of the Fermi surface of beryllium is proposed. It explains correctly the recent experimental data on observation of non-homogeneous phase in beryllium at the conditions of strong dHvA effect when the strong correlation of electron gas results in instability of homogeneous phase and formation of Condon domain structure.Comment: 5 pages, 4 figure

Shape-dependent Depinning of a Domain Wall by a Magnetic Field and a Spin-Polarized Current

The effect of sample shape on the depinning of the domain wall (DW) driven by an applied magnetic field or a spin-polarized current is studied theoretically. The shape effect resulting from the modulation of the sample width (geometric pinning) can essentially affect the DW depinning. We found a good agreement between the ratios of the critical values of the magnetic field and the spin-polarized current predicted by the theory and measured in the experiment.Comment: 9 pages, 5 figure

Domain Walls in a Tetragonal Chiral p-Wave Superconductor

Domain walls in a tetragonal chiral p-wave superconductors with broken time reversal symmetry are analyzed in the framework of the Ginsburg-Landau theory. The energy and the jump of the magnetic induction on the wall were determined for different types of walls as functions of the parameters of the Ginzburg-Landau theory and orientation of the domain wall with respect to the crystallographic axes. We discuss implications of the analysis for $Sr_{2}RuO_{4}$, where no stray magnetic fields from domain walls were detected experimentally.Comment: 8 pages, 2 figure

Giant parametric amplification of the nonlinear response in a single crystal of beryllium in a quantizing magnetic field

The nonlinear response to an ac magnetic field with and without parametric pumping was studied experimentally on a rod-like beryllium single crystal at low temperatures in a quantizing magnetic field applied parallel to the hexagonal axis. At low temperatures (≤ 3 K) giant parametric amplification of the nonlinear response is observed in narrow windows near de Haas– van Alphen (dHvA) beating antinodes where the amplitude of the magnetic oscillations is maximal. This effect is of threshold character with respect to the amplitude of the dHvA oscillations and occurs as a result of a diamagnetic phase transition of a strongly correlated electron gas into nonuniform state with formation of Condon domain structure. It is shown that the nonuniform phase appears periodically in a magnetic field. The components of rectified signal field reproduce the envelope of H–T critical curves and can be used for reconstruction of diamagnetic phase diagrams

Giant parametric amplification of the nonlinear response in a single crystal of beryllium in a quantizing magnetic field

The nonlinear response to an ac magnetic field with and without parametric pumping was studied experimentally on a rod-like beryllium single crystal at low temperatures in a quantizing magnetic field applied parallel to the hexagonal axis. At low temperatures (≤ 3 K) giant parametric amplification of the nonlinear response is observed in narrow windows near de Haas– van Alphen (dHvA) beating antinodes where the amplitude of the magnetic oscillations is maximal. This effect is of threshold character with respect to the amplitude of the dHvA oscillations and occurs as a result of a diamagnetic phase transition of a strongly correlated electron gas into nonuniform state with formation of Condon domain structure. It is shown that the nonuniform phase appears periodically in a magnetic field. The components of rectified signal field reproduce the envelope of H–T critical curves and can be used for reconstruction of diamagnetic phase diagrams