LARGE RANGE OF VALIDITY OF LINEAR ELASTICITY OF THE VORTEX LATTICE IN HIGH-T(C) SUPERCONDUCTORS

Linear elasticity theory of the vortex lattice in anisotropic and layered superconductors has a much wider range of applicability than in isotropic superconductors. This finding is used to calculate the energy barrier for thermally activated depinning of vortices from columnar pins along the c axis. The activation energy of these most effective fine pins is strongly reduced by anisotropy. For very large anisotropy as in Bi2Sr2CaCu2O8, the length of the depinning vortex segment formally becomes shorter than the layer spacing; this means that the pancake vortices in the CuO layers depin individually.