Related papers: Superconducting transition in disordered granular …
It is shown that the transition to the low temperature superconducting state in a 3D metal at high magnetic field is smeared dramatically by thermal fluctuation of the superconducting order parameter. The resulting superconducting-to-normal…
We examine the idea, postulated by Phillips et al., that a finite resistivity in $T \to 0$ limit in disordered granular superconducting (SC) films is explained as a consequence of the absence of phase stiffness in a phase glass (PG)…
When a Josephson junction array is built with hybrid superconductor/metal/superconductor junctions, a quantum phase transition from a superconducting to a two-dimensional (2D) metallic ground state is predicted to happen upon increasing the…
The electric conductivities in glass phases of three-dimensional (3D) granular superconductors in magnetic fields are examined based on a quantum disordered Josephson-junction array. A correct inclusion of the Ohmic dissipative dynamics…
The two-dimensional XY gauge glass, which describes disordered superconducting grains in strong magnetic fields, is investigated, with regard to the possibility of a glass transition. We compute the glass susceptibility and the correlation…
The position of a field-tuned superconductor-insulator quantum transition occuring in disordered thin films is examined within the mean field approximation. Our calculation shows that the microscopic disorder-induced reduction of the…
The superconducting transition in presence of strong columnar disorder parallel to the magnetic field is considered. A solvable model appropriate for description of the broad crossover regime towards the true "glassy" critical behavior is…
Motivated by a {\it mean field-like} resistive behavior in magnetic fields commonly seen in various superconducting (SC) cuprates and organics with strong fluctuation, {\it quantum} SC fluctuation effects on resistive behaviors are…
It is shown that, within a Ginzburg-Landau (GL) formalism, the superconducting fluctuation is insulating at zero temperature even if the fluctuation dynamics is metallic (dissipative). Based on this fact, the low temperature behavior of the…
The superconducting transition of a two-dimensional (2D) Josephson junction array exposed to weak magnetic fields has been studied experimentally. Resistance measurements reveal a superconducting-resistive phase boundary in serious…
The effect of disorder is investigated in granular superconductive materials with strong and weak links. The transition is controlled by the interplay of the \emph{tunneling} $g$ and \emph{intragrain} $g_{intr}$ conductances, which depend…
We discuss the occurrence of crossing points in the magnetization - temperature $(m,T$) plane within the framework of critical phenomena. It is shown that in a two-dimensional superconducting slab of thickness $d_{s}$ $m_{z}(\delta)$ versus…
Vortex fluctuations in the $La_{2-x}Sr_{x}CuO_{4+\delta}$ system have been studied as a function of magnetic field, temperature and carrier concentration in order to determine the dimensionality of the fluctuations. For a $x=0.10$ sample,…
A vortex-glass transition due to point disorder in layered superconductors is studied for the case with an applied field {\it parallel} to the layers. Our calculation of tilt responses indicates that, irrespective of the magnitude of the…
By using a Ginzburg-Landau functional in the Gaussian approximation, we calculate the energy of superconducting fluctuations above the transition, at zero external magnetic field, of a system composed by a small number $N$ of parallel…
Phase transitions of a flux lattice in layered superconductors with magnetic field perpendicular to the layers and in presence of disorder are studied. We find that disorder generates a random Josephson coupling between layers which leads…
The interplay of quantum fluctuations and dissipation in chains of mesoscopic superconducting grains is analyzed, and the results are also applied to nanowires. It is shown that in 1-d arrays of resistively shunted Josephson junctions, the…
Resistive behaviors at nonzero temperatures (T > 0) reflecting a quantum vortex-glass (VG) transition (the so-called field-tuned superconductor-insulator transition at T=0) are studied based on a quantum Ginzburg-Landau (GL) action for a…
The superconducting-insulator transition is simulated in disordered networks of Josephson junctions with thermally activated Arrhenius-like resistive shunt. By solving the conductance matrix of the network, the transition is reproduced in…
Magnetoconductivity of the disordered two- and three-dimensional superconductors is addressed at the onset of superconducting transition. In this regime transport is dominated by the fluctuation effects and we account for the interaction…