Critical Behavior of the Flux-line Tension in Extreme Type-II Superconductors

a r X i v :c o n d -m a t /9604152v 1 24 A p r 1996CRITICAL BEHA VIOR OF THE FLUX-LINE TENSION IN EXTREME TYPE-II SUPERCONDUCTORS J. P. Rodriguez Theoretical Division, Los Alamos National Laboratory, Los Alamos, NM 87545.*Abstract The entropic corrections to the flux-lineenergy of extreme type-II superconductors are computed using a schematic dual Villain model description of the fluxquanta. We findthat the temperature profileof the lower-critical fieldvanishes polynomially at the transition with an exponent ν∼=2/3in the isotropic case, while it exhibits an inflectionpoint for the case of weakly coupled layers in parallel magnetic field.It is argued that vestiges of these effectshave already been observed in high-temperature superconductors. PACS Indices:74.20.De, 74.60.-w, 11.15.Ha, 75.10.Hk