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Three different contributing mechanisms have been considered to calculate the magnetization (M) of p-type Pb1-xMnxSe for a hole density of p = 5 × 1018 cm−3and n-type Pb1-xMnxS for an electron density of n = 6 × 1018 cm−3.The first mechanism comes from the valence band diamagnetism which is calculated in a frame of the two-band model. The second mechanism which we consider arises from the spin densities of holes and electrons and we use a six-level k →. π → theory in second-order perturbation theory in the effective mass representation. The third mechanism is the impurity Mn+2 ions contribution, and we consider small clusters consisting of one, two and three spins to evaluate it. The three spin clusters include both open and closed types. It has been observed that the former two mechanisms contribute very little to the magnetization compared to the latter one. However, their importance cannot be ignored because they provide a deeper understanding of the underlying physical mechanisms involved with carrier spin polarization and orbital diamagnetism of the host matrix, in which the Mn+2 spins are embedded. Good agreement of our theory with experiment is the other interesting and distinct feature of this work. [ABSTRACT FROM AUTHOR]

We investigate the spin mixing dynamics of a spin–orbit coupled Bose–Einstein condensate by using a variational approach. It is shown that the spin mixing dynamics can be well described by an internal Josephson equation. In the nonzero momentum phase, the spin mixing dynamics leads to a spin polarization, i.e., most atoms are suppressed in the one of the two spin states. In the zero momentum phase, the internal Josephson oscillation between the two spin states takes place. Thus, the coupling effects of spin–orbit coupling, Raman coupling and atomic interaction can result in the transition between the spin polarization and the internal Josephson oscillation of the two spin states, which provide a theoretical evidence for elaborating the spin mixing dynamics. Moreover, at the phase transition point, the oscillation period of the spin mixing dynamics tends to infinity. This can be used to explore the phase transition experimentally. The accurate manipulation of the spin mixing dynamics can provide a theoretical evidence for designing the atomic device. [ABSTRACT FROM AUTHOR]

We report first-principles calculations of the elastic properties, electronic structure and magnetic behavior performed over the Ba2NiMoO6 double perovskite. Calculations are carried out through the full-potential linear augmented plane-wave method within the framework of the Density Functional Theory (DFT) with exchange and correlation effects in the Generalized Gradient and Local Density Approximations, including spin polarization. The elastic properties calculated are bulk modulus (B), the elastic constants (C11, C12 and C44), the Zener anisotropy factor (A), the isotropic shear modulus (G), the Young modulus (Y) and the Poisson ratio (υ). Structural parameters, total energies and cohesive properties of the perovskite are studied by means of minimization of internal parameters with the Murnaghan equation, where the structural parameters are in good agreement with experimental data. Furthermore, we have explored different antiferromagnetic configurations in order to describe the magnetic ground state of this compound. The pressure and temperature dependence of specific heat, thermal expansion coefficient, Debye temperature and Grüneisen parameter were calculated by DFT from the state equation using the quasi-harmonic model of Debye. A specific heat behavior CV ≈ CP was found at temperatures below T = 400 K, with Dulong-Petit limit values, which is higher than those, reported for simple perovskites. [ABSTRACT FROM AUTHOR]

Our results for the scattering and thermophysical properties of spin-polarized atomic hydrogen $$(\hbox {H}{\downarrow })$$ have been presented in the temperature range 0.01-10 K using the Galitskii-Migdal-Feynman formalism. These results include the quantum second virial coefficient, the average total and viscosity cross sections, the viscosity, the diffusion coefficient, and the thermal conductivity. The calculations have been undertaken using three triplet-state potentials: Morse-type, Silvera and Born-Oppenheimer potentials. The Morse potential is less attractive and very simple, but less accurate to describe spin-polarized atomic hydrogen. That explains the differences between it and the other two potentials, which are clearly better. From the results of the average total cross sections, it is concluded the $$\hbox {H}{\downarrow }$$ remains a gas even at low temperature. The viscosity, the thermal conductivity, and the diffusion coefficients of $$\hbox {H}{\downarrow }$$ increase in all cases with increasing temperature. [ABSTRACT FROM AUTHOR]

The quantitative analysis of a low-temperature minimum of the resistivity of $$\mathrm {La_{0.5}Ca_{0.4}Li_{0.1}MnO_3}$$ under high magnetic fields (up to 14 T) was performed. It was shown that the behavior of resistivity and magnetoresistivity at low temperature and high magnetic field can be fitted well by a spin-polarized intergrain tunneling model. [ABSTRACT FROM AUTHOR]

We study the spin-dependent transmission through a potential barrier in a zigzag graphene nanoribbon. In particular, we consider the effect of the magnetic order of the ribbon induced by the modulation of the local density introduced by the barrier. We model the system using an Anderson-Hubbard model that we treat in the mean field approximation. We solve this problem self-consistently and calculate the transmission coefficient using the recursive Green function method. We find that Fano-like interference dips appear on one of the spin channels as the result of the presence of spin polarized edge states in the barrier. [ABSTRACT FROM AUTHOR]

We have investigated point contacts between ferromagnetic Fe and different BCS-type superconductors using Andreev reflection spectroscopy. With the standard BTK-type analysis, the extracted spin polarization of Fe does not depend on the superconductor and agrees well with literature data. However, the characteristics of the Andreev reflection spectra vary with the superconductor. While most of the contacts with the strong superconductors Nb and Ta appear to be barely affected by the presence of Fe, the contacts with weaker superconductors Sn and Al have a reduced critical temperature $$T_\mathrm{c}$$ and occasionally a second superconducting transition at still lower temperature, and contacts with the weakest superconductor Zn have strongly reduced superconducting anomalies. We propose that this variation is related to the magnetic field generated by the ferromagnetic electrode, which can also affect the extracted spin polarization. [ABSTRACT FROM AUTHOR]