|Title||Ginzburg-Landau theory of the superheating field anisotropy of layered superconductors|
|Publication Type||Journal Article|
|Year of Publication||Submitted|
|Authors||Liarte, Danilo B., and Sethna James P.|
We investigate the effects of material anisotropy on the superheating field of layered superconductors. We provide an intuitive argument both for the existence of a superheating field, and its dependence on anisotropy, for κ=λ/ξ (the ratio of magnetic to superconducting healing lengths) both large and small. We see that the superheating field shows significant anisotropy only when the anisotropy is large and the Ginzburg-Landau parameter κ is small. We then conclude that only small anisotropies in the superheating field are expected for typical unconventional superconductors near the critical temperature. Using a generalized form of Ginzburg Landau theory, we do a quantitative calculation for the anisotropic superheating field by mapping the problem to the isotropic case, and present a phase diagram in terms of anisotropy and κ, showing type I, type II, or mixed behavior (within Ginzburg-Landau theory), and regions where each asymptotic solution is expected. We estimate anisotropies for a number of different materials, and discuss the importance of these results for radio-frequency cavities for particle accelerators.
Ginzburg-Landau theory of the superheating field anisotropy of layered superconductors