Related papers: Phase transitions in the mesoscopic superconductin…
The Ginzburg-Landau equations are solved for ideally periodic vortex lattices in superconducting films of arbitrary thickness in a perpendicular magnetic field. The order parameter, current density, magnetic moment, and the 3-dimensional…
The phase transition in frustrated spin systems is a fascinated subject in statistical physics. We show the result obtained by the Wang-Landau flat histogram Monte Carlo simulation on the phase transition in the fully frustrated simple…
In this paper we study the Ginzburg-Landau (GL) equation for Fermi liquid superconductors with strong Landau interactions $F_0$ and $F_1$. We show that Landau interactions renormalize two parameters entering the GL equation leading to…
We study the thermodynamics of the diffusive SFS trilayer composed of thin superconductor (S) and ferromagnet (F) layers. On the basis the self-consistent solutions of nonlinear Usadel equations in the F and S layers we obtain the…
Finite size scaling for a first order phase transition where a continuous symmetry is broken is developed using an approximation of Gaussian probability distributions with a phenomenological "degeneracy" factor included. Predictions are…
The pressure dependence of the order parameter in superfluid $^3$He is amazingly simple. In the Ginzburg-Landau regime, i.e. close to $T_c$, the square of the order parameter can be accurately measured by its proportionality to NMR…
A simplified Ginzburg-Landau theory is presented to study generally a coupling of a first-order phase transition (FOPT) to a second-order phase transition (SOPT). We show analytically that, due to the coupling between the two phase…
The possibility of a magnetic phase transition in Heisenberg, Hubbard, and s-f (Kondo-lattice) films is investigated. It is shown that, for any finite temperature and any finite number of layers, the magnetization within every layer must…
We obtain an almost complete understanding of the mean-field phase diagram of the two-dimensional Hubbard model on a square lattice with a sizable next-nearest neighbor hopping and a moderate interaction strength. In particular, we clarify…
The single-particle energy spectrum of a two-dimensional electron gas in a perpendicular magnetic field consists of equally-spaced spin-split Landau levels, whose degeneracy is proportional to the magnetic field strength. At integer and…
We study the vortex state in a magnetic field parallel to the $c$ axis in the framework of the extended Ginzburg Landau equation. We find the vortex acquires a fourfold modulation proportional to $\cos(4\phi)$ where $\phi$ is the angle…
The Halperin-Lubensky-Ma (HLM) effect of a fluctuation-induced change of the order of phase transition in thin films of type I superconductors with relatively small Ginzburg-Landau number $\kappa$ is considered. Numerical data for the free…
We study the order of the phase transition in the 3d U(1)+Higgs theory, which is the Ginzburg-Landau theory of superconductivity. We confirm that for small scalar self-coupling the transition is of first order. For large scalar…
A model of two-species bosons moving on the sites of a lattice is studied at nonzero temperature, focusing on magnetic order and superfluid-insulator transitions. Firstly, Landau theory is used to find the general structure of the phase…
We employ Monte Carlo simulations to study a generalized three-dimensional complex $psi|^4 theory of Ginzburg-Landau form and compare our numerical results with a recent quasi-analytical mean-field type approximation, which predicts…
We study the finite temperature electroweak phase transition in an external hypercharge U(1) magnetic field H_Y, using lattice Monte Carlo simulations. For sufficiently small fields, H_Y/T^2 < 0.3, the magnetic field makes the first order…
The effect of the external field on the weakly-discontinuous first-order phase transition is analyzed in the frame of the Landau theory. The transformation of the free energy expansion as a power series in the order parameter is suggested…
The phase transition of hard-sphere Heisenberg and Neutral Hard spheres mixture fluids has been investigated with the density functional theory in mean-field approximation (MF). The matrix of second derivatives of the grand canonical…
We consider polymers made of magnetic monomers (Ising or Heisenberg-like) in a good solvent. These polymers are modeled as self-avoiding walks on a cubic lattice, and the ferromagnetic interaction between the spins carried by the monomers…
Using the non-linear Ginzburg-Landau (GL) theory, we study the magnetic response of different shaped samples in the field-cooled regime (FC). For high external magnetic fluxes, the conventional diamagnetic response under cooling down can be…