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In the present work, we will study the effect of dimensionality (i.e 2 + 1 and 3 + 1) has on the different types of coupling in a two-band superconducting system, specifically for the Josephson, bi-quadratic and weak type couplings. This study will be oriented to a ZFC (Zero-Field-Cooling) process and we will see the effect that the variation of temperature for three special cases of the external field (fixed, H < H 1 , H = H 1 and H > H 1) has on the order parameter ψ , phase ψ , magnetization M and free energy G (T) in these superconductors of multibands and a comparison between the behavior of these electronic and thermodynamic variables. This analysis will be carried out using the solution of time-dependent two bands Ginzburg-Landau equations (2B-TDGL). • Dimensionality (2 + 1 and 3 + 1), the type of couplings (Josephson, bi-quadratic and weak), and the temperature of the sample. • Two bands Ginzburg-Landau equations for a two-band system (2B-TDGL). [ABSTRACT FROM AUTHOR]

We used the Curie–Weiss mean-field approximation to study the effects of random single-ion anisotropy and random magnetic field in the phase diagram as well as in the thermodynamic properties of the spin-7/2 Blume–Capel model. The phase diagrams are presented in the planes temperature versus single-ion anisotropy and temperature versus magnetic field, temperature versus random parameters. The dependencies of magnetization are studied as a function of temperature and single-ion anisotropy. • Phase diagrams of the system with a random anisotropies and random field were obtained. • To investigate the system, Curie–Weiss mean-field approximation were used. • First- and second-order phase transition lines for different anisotropies were found. • Tricritical behavior for some values of anisotropy and magnetic field were observed. [ABSTRACT FROM AUTHOR]

In the present work, we will study the superconducting properties of a mesoscopic three-dimensional prism with square transversal section under an external magnetic field in both Zero-Field Cooling (ZFC) and Field-Cooling (FC) process. The studied sample is a three-band system (with three condensates ψ 1 , ψ 2 , ψ 3 ), in which we take a Josephson type inter-band coupling simulated via γ parameter. We analyze the magnetization, superconducting electronic density and free Gibbs energy considering both processes. As results, we found an interesting tunneling of vortex and anti-vortex between the bands, and vortex cluster configuration in the sample. This behaviour is due to the non-monotonic interaction between the bands. [ABSTRACT FROM AUTHOR]