Related papers: A minimal size for granular superconductors
In Ginzburg-Landau theory, a strong magnetic field is responsible for the breakdown of superconductivity. This work is concerned with the identification of the region where superconductivity persists, in a thin shell superconductor modeled…
We consider a quantum system consisting of a regular chain of elementary subsystems with nearest neighbor interactions and assume that the total system is in a canonical state with temperature $T$. We analyze under what condition the state…
We investigate the suppression of the superconducting transition temperature due to Coulomb repulsion in granular metallic systems at large tunneling conductance between the grains, $g_{T}\gg 1$. We find the correction to the…
We derive the linearized Ginzburg-Landau (GL) equation for a curved ultra-thin superconducting film in the presence of a magnetic field. By introducing a novel transverse order parameter that varies slowly along the film with the…
The Ginzburg-Landau model is a phenomenological description of superconductivity. A crucial feature of type-II superconductors is the occurrence of vortices, which appear above a certain value of the applied magnetic field called the first…
Little-Parks oscillation of a M\"obius strip (or ring equivalently) made of a superconductor is studied based on Ginzburg-Landau theory. It is shown that, if the strip is wide enough, a novel state appears when the number of magnetic flux…
The noncentrosymmetric superconductor AuBe have been investigated using the magnetization, resistivity, specific heat, and muon-spin relaxation/rotation measurements. AuBe crystallizes in the cubic FeSi-type B20 structure with…
We review some recent extensions of the Ginzburg-Landau model able to describe several properties of non-conventional superconductors. In the first extension, s-wave superconductors endowed with two different critical temperatures are…
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 present transport measurements on quench condensed granular Pb films in which the grains are 40-80\AA in diameter. These films show a cross over from an insulator to a superconductor behavior as the nominal thickness of the layer is…
We compute the $L^2$-norm of the minimizer of the Ginzburg-Landau functional in a planar domain with a finite number of corners. Our computations are valid for a uniform applied magnetic field, large Ginzburg-Landau parameter and in the…
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…
Based on the Hubbard model in the framework of non-phonon kinematical mechanism and taking into account the discreetness of an electronic energy spectrum, the superconducting critical temperature of a mesoscopic high-$T_{c}$ sphere is…
Temperature dependence of the lower critical field Hc1 (T) for the superconducting magnesium diboride, MgB2, is studied in the vicinity of Tc by using a two-band Ginzburg-Landau (G-L) theory. Theoretically calculated Hc1 (T) near Tc…
Superconductivity has been found in RuN films obtained by reactive magnetron sputtering. This is a novel member of the metal nitride superconductors family. The critical temperature of the superconducting transition varies depending on the…
A narrow intragrain phase-lock transition was observed in RuSr2EuCu2O8 under a magnetic field H up to a few Tesla. The corresponding transition temperature, T2, decreases rapidly (about 100 K/T at low fields) with H indicating that the…
Granular aluminum, which consists of nanometer-sized aluminum grains separated by aluminum oxide, is a peculiar superconductor. Its phase diagram as function of normal-state resistivity features a superconducting dome with a maximum…
Porous magnesium diboride samples have been prepared by the heat treatment of a pressed mixture of Mg and MgB2 powders. It was found that linked superconducting structure is formed down to the minimum normalized density gamma= d/do= 0.16…
The superconducting properties of a layered system are analyzed for the cases of zero- and non-zero angular momentum of the pairs. The effective thermodynamic potential for the quasi-2D XY-model for the gradients of the phase of the order…
The shape of experimentally observed R(T) transition of thin superconducting wires is analyzed. Broadening of the transition in quasi-1-dimensional superconducting channels is typically associated with phase slip mechanism provided by…