Increasing the critical temperature of a superconductor by curving its surface
voor Vaste-Stoffysica en Magnetisme Katholieke Universiteit Leuven
B-3001 Leuven, Belgium
Accepted: 25 July 2000
Using Ginzburg-Landau theory it is predicted that the critical temperature of a mesoscopic superconductor with surface enhancement can be increased significantly with respect to the bulk , by introducing surface curvature. While confinement and reduction of the dimensionality lead to a critical-point shift which decays exponentially with the ratio of sample size to coherence length, surface curvature gives rise to a more important algebraic shift proportional to the curvature . As an example, order-of-magnitude estimates for the increase of are given for cold-worked mesoscopic InBi cylindrical wires and spherical grains.
PACS: 74.20.De – Phenomenological theories (two-fluid, Ginzburg-Landau, etc.) / 74.76.-w – Superconducting films / 68.35.Rh – Phase transitions and critical phenomena
© EDP Sciences, 2000