Thermal fluctuation and melting of the vortex lattice in oxide superconductors

The thermal fluctuation of the vortex positions in type-II superconductors with large Ginzburg-Landau parameter {κ} and weak pinning is drastically increased when calculated from the correct nonlocal elasticity of the vortex lattice. As compared to the usual (local) elastic result, the mean-square shear strain and vortex displacements increase by a factor of {}(B{}/Bc1{)}1/2/(1-B/{B}c2)1/2 (B{} is the flux density, Bc1 and Bc2 are the lower and upper critical fields). The melting temperature of the vortex lattice is reduced by the same factor.