相关论文: Influence of fluctuations on the superfluid densit…
It is expected that in the interior of compact stars a proton superconductor coexists with and couples to a neutron superfluid. Starting from a field-theoretical model for two complex scalar fields - one of which is electrically charged -…
We conpare predictions of the mean-field theory of supercnductivity for metallic systems on the border of a density instability for cubic and tetragonal lattices. The calculations are based on a parametrisation of an effective interaction…
Em geral, quando a teoria fenomenol\'ogica de Ginzburg-Landau para supercondutores \'e trabalhada, pouco se esclarece aos alunos sobre a origem da mesma. Esta tem como base conceitos termodin\^amicos como fen\^omenos cr\'iticos e…
Many successful theories of liquids near the melting temperature assume that small length scale density fluctuations follow Gaussian statistics. In this paper I present numerical investigations of fluctuations in the supercooled viscous…
New, superfluid specific additive integral of motion is found. This facilitates investigation of general thermodynamic equilibrium conditions for superfluid. The analysis is performed in an extended space of thermodynamic variables…
The modified Ginzburg-Landau equations are used to study some fundamental problems for the high temperature superconductors. The derivations of these fundamental equations are summarized and the layered features of the sample were taken…
Classic and recent results for gauge effects on the properties of the normal-to-superconducting phase transition in bulk and thin film superconductors are reviewed. Similar problems in the description of other natural systems (liquid…
We study the amplitude and phase fluctuations of the Ginzburg-Landau quasiorder parameter for superconductors in two spatial dimensions. Starting from the mean-field critical temperature $T_{\mathrm{c}0}$, we calculate the beyond-mean-field…
We study the flux-flow Hall effect and thermomagnetic transport near the upper critical field \hctwo\ in extreme type-II superconductors starting from a suitable generalization of the time dependent Ginzburg-Landau equations. We explicitly…
The magnetization around the superconducting transition was measured in a Tl$_{0.5}$Pb$_{0.5}$Sr$_2$CaCu$_2$O$_7$ crystal affected by a considerable reduction ($\sim$55%) of its effective superconducting volume fraction but still with a…
Phase fluctuations of the superconducting order parameter play a larger role in the cuprates than in conventional BCS superconductors because of the low superfluid density of a doped insulator. In this paper, we analyze an XY model of…
We develop an optimized perturbation theory for the Ginzburg - Landau description of thermal fluctuations effects in the vortex liquids. Unlike the high temperature expansion which is asymptotic, the optimized expansion is convergent.…
A wide range of quasi-one-dimensional materials, consisting of weakly coupled chains, undergo three-dimensional phase transitions that can be described by a complex order parameter. A Ginzburg-Landau theory is derived for such a transition.…
By considering the Ginzburg-Landau model, compactified in one of the spatial dimensions, and using a modified Matsubara formalism, we determine the dependence of the superconducting transition temperature (T_c) of a film as a function of…
Density-wave instabilities have been observed and studied in a multitude of materials. Most recently, in the context of unconventional superconductors like the iron-based superconductors, they have excited considerable interest. We analyze…
Fluctuations are important near phase transitions, where they can be difficult to describe quantitatively. Superconductivity in mesoscopic rings is particularly intriguing because the critical temperature is an oscillatory function of…
The critical fluctuations in a mesoscopic superconducting ring are studied within the Ginzburg-Landau approach. The nonlocal conductivity as well as the specific heat are calculated as functions of the magnetic flux $\Phi$ through the ring.…
The superconducting state of an infinitely long superconducting cylinder surrounded by a medium which enhances its superconductivity near the boundary is studied within the nonlinear Ginzburg-Landau theory. This enhancement can be due to…
We study the influence of thermal fluctuations on the magnetic behavior of square mesoscopic superconductors. The strength of thermal fluctuations are parameterized using the Ginzburg number, which is small ($G_i \approx 10^{-10}$) in…
The properties of a vortex in a rotating superfluid Fermi gas are studied in the unitary limit. A phenomenological approach based on Ginzburg-Landau theory is developed for this purpose. The density profiles, including those of the normal…