We prove that a system of discrete two-dimensional 2D in-plane dipoles with four possible orientations, interacting via a three-dimensional 3D dipole-dipole interaction plus a nearest neighbor ferromagnetic term, has periodic striped ground states. As the strength of the ferromagnetic term is increased, the size of the stripes in the ground state increases, becoming infinite, i.e., giving a fer...

The switching of magnetic layers is studied under the action of a spin current in a ferromagnetic metal– nonmagnetic metal–ferromagnetic metal spin valve. We find that the main contribution to the switching comes from the nonequilibrium exchange interaction between the ferromagnetic layers. This interaction defines the magnetic configuration of the layers with minimum energy and establishes the...

The double-exchange model, which has been extensively studied in the context of colossal magneto-resistance in perovskite manganese oxides, is known to exhibit a ferromagnetic metallic state at low temperatures because of the interplay between localized moments and itinerant electrons through the Hund’s-rule coupling. Here we investigate numerically the ferromagnetic transition in the double-ex...

We perform a numerical study using both determinantal and constrain path Monte Carlo methods to investigate the magnetic and pairing properties of the single-band Hubbard model on the triangular lattice. We find that the system in the filling region n =1.5–1.85 shows a short-ranged ferromagnetic correlation, and the on-site Coulomb interaction tends to strengthen ferromagnetic fluctuation sligh...

We study the influence of magnetic scattering on the Josephson critical current, Ic, in a superconductor/ferromagnetic metal/superconductor (SFS) junction by a tunneling Hamiltonian approach. An analytical formula of Ic is given in the fourth order perturbation theory as regards the tunneling matrix element. The Ic exhibits the damped oscillatory dependence on the thickness of the ferromagnetic...

As the first magnetic random access memories are finding their way onto the market, an important issue remains to be solved: the current density required to write magnetic bits becomes prohibitively high as bit dimensions are reduced. Recently, spin-orbit torques and the spin-Hall effect in particular have attracted significant interest, as they enable magnetization reversal without high curren...

We present a comprehensive study relating the nanostructure of Ge0.95Mn0.05 films to their magnetic properties. The formation of ferromagnetic nanometer-sized inclusions in a defect-free Ge matrix fabricated by low-temperature molecular beam epitaxy is observed down to substrate temperatures TS as low as 70 °C. A combined transmission electron microscopy and electron energy-loss spectroscopy an...

Superconductivity has again become a challenge following the discovery of unconventional superconductivity. Resistance-free currents have been observed in heavy-fermion materials, organic conductors and copper oxides. The discovery of superconductivity in a single crystal of UGe2, ZrZn2 and URhGe revived the interest in the coexistence of superconductivity and ferromagnetism. The experiments in...

In order to improve the sensitivity of online magnetic flux leakage (MFL) testing for steel pipe, a sensing method based on the magnetic guiding effect is proposed and investigated in this paper. Compared to the conventional contact sensing method using a non-ferromagnetic support, the proposed method creatively utilizes a ferromagnetic one to guide more magnetic flux to leak out. Based on Hopk...