The longitudinal resistivity of two-dimensional 2D electrons placed in strong magnetic field is significantly reduced by applied electric field, an effect which is studied in a broad range of magnetic fields B and temperatures T in GaAs quantum wells with high electron density. The data are found to be in good agreement with theory, considering the strong nonlinearity of the resistivity as the ...

The anisotropic physical properties of single crystals of orthorhombic PtSn 4 are reported for magnetic fields up to 140 kOe, applied parallel and perpendicular to the crystallographic b axis. The magnetic susceptibility has an approximately temperature-independent behavior and reveals an anisotropy between the ac plane and b axis. Clear de Haas-van Alphen oscillations in fields as low as 5 kOe...

Cellular automata (CA) models account for the power-law distributions found for solar flare hard X-ray observations, but their physics has been unclear. We examine four of these models and show that their criteria and magnetic field distribution rules can be derived by discretizing the MHD diffusion equation as obtained from a simplified Ohm’s law. Identifying the discrete MHD with the CA model...

Astrophysical objects with negligible resistivity are often threaded by large scale magnetic fields. The generation of these fields is somewhat mysterious, since a magnetic field in a perfectly conducting fluid cannot change the flux threading a fluid element, or the field topology. Classical dynamo theory evades this limit by assuming that magnetic reconnection is fast, even for vanishing resi...

We present a Lagrangian-Eulerian strategy for proving uniqueness and local existence of solutions of limited smoothness for a class of incompressible hydrodynamic models including Oldroyd-B type complex fluid models and zero magnetic resistivity magneto-hydrodynamics equations.

We present an electrical transport study of the 2-dimensional (2D) organic conductor τ -(P-(S,S)-DMEDT-TTF)2(AuBr)2 (AuBr2)y (where y ∼ 0.75) at low temperatures and high magnetic fields. The inter-plane resistivity ρzz increases with decreasing temperature, with the exception of a slight anomaly at 12 K. Under a magnetic field B, both ρzz and the in-plane resistivity plane ρxx show a pronounce...

The nature of phase separation in Pr(0.5)Sr(0.5)MnO(3) has been probed by linear, as well as nonlinear, magnetic susceptibilities and resistivity measurements across the second order paramagnetic to ferromagnetic transition (T(C)) and first order ferromagnetic to antiferromagnetic transition (T(N)). We found that the ferromagnetic (metallic) clusters, which form at T(C), continuously decrease t...

Iron(II) complexes with neutral and oxidized tetrathiafulvalene (TTF) moieties were prepared and X-ray crystallographic analyses, magnetic and electrical resistivity measurements suggested an interaction of spin transition and electrical conductivity.

The energy of the stochastic magnetic field is bounded from below by a topological quantity expressing the degree of linkage of the field lines. When the bound is saturated one can assume that the storage of a certain magnetic energy requires a minimal degree of topologi-cal complexity. It is then possible to infer a connection between the helicity content and the average curvature of the magne...

We present the results of fieldand temperature-dependent resistivity r and magnetization M measurements which show that colossal magnetoresistance in semimetallic EuB6 is not associated with its bulk Curie temperature TC512.6 K, determined by a scaling analysis of M (H ,T), but with a second phase transition at TM515.5 K. We propose that metallization occurs at TM via the overlap of magnetic po...