Vortex wandering among splayed columnar defects - art. no. 144512

We investigate the scaling properties of single flux lines in a random pinn ing landscape consisting of splayed columnar defects. Such correlated defec ts can be injected into type II superconductors by inducing nuclear fission or via direct heavy ion irradiation. The result is often very efficient pi nning of the vortices which gives, e.g., a strongly enhanced critical curre nt. The wandering exponent zeta and the free energy exponent omega of a sin gle flux line in such a disordered environment are obtained analytically fr om scaling arguments combined with extreme-value statistics. In contrast to the case of point disorder, where these exponents Lire universal, we find a dependence of the exponents on details in the probability distribution of the low lying energies of the columnar defects. The analytical results sho w excellent agreement with numerical transfer matrix calculations in two an d three dimensions.