Physics – Condensed Matter – Superconductivity
Scientific paper
2000-09-21
Physics
Condensed Matter
Superconductivity
37 pages, 5 figures, accepted for PRB
Scientific paper
10.1103/PhysRevB.62.14359
Within the Ginzburg-Landau approach a theoretical study is performed of the effects of confinement on the transition to superconductivity for type-I and type-II materials with surface enhancement. The superconducting order parameter is characterized by a negative surface extrapolation length $b$. This leads to an increase of the critical field $H_{c3}$ and to a surface critical temperature in zero field, $T_{cs}$, which exceeds the bulk $T_c$. When the sample is {\em mesoscopic} of linear size $L$ the surface induces superconductivity in the interior for $T < T_{c}(L)$, with $T_c(L) > T_{cs}$. In analogy with adsorbed fluids, superconductivity in thin films of type-I materials is akin to {\em capillary condensation} and competes with the interface delocalization or "wetting" transition. The finite-size scaling properties of capillary condensation in superconductors are scrutinized in the limit that the ratio of magnetic penetration depth to superconducting coherence length, $\kappa \equiv \lambda/\xi $, goes to zero, using analytic calculations. While standard finite-size scaling holds for the transition in non-zero magnetic field $H$, an anomalous critical-point shift is found for H=0. The increase of $T_c$ for H=0 is calculated for mesoscopic films, cylindrical wires, and spherical grains of type-I and type-II materials. Surface curvature is shown to induce a significant increase of $T_c$, characterized by a shift $T_c(R)-T_c(\infty)$ inversely proportional to the radius $R$.
Indekeu Joseph O.
Montevecchi E.
No associations
LandOfFree
Effects of confinement and surface enhancement on superconductivity does not yet have a rating. At this time, there are no reviews or comments for this scientific paper.
If you have personal experience with Effects of confinement and surface enhancement on superconductivity, we encourage you to share that experience with our LandOfFree.com community. Your opinion is very important and Effects of confinement and surface enhancement on superconductivity will most certainly appreciate the feedback.
Profile ID: LFWR-SCP-O-131278