Magnetic Flux Line Lattices in the Cuprate Superconductors

Abstract

In this article we discuss a variety of recent experiments on the static and dynamic properties of vortices and flux-line lattices in the mixed state of the copper-oxide superconductors. The experiments are of two basic types; the first images the magnetic flux patterns with magnetic decoration which gives information about static structures and the second explores the dynamics of vortices through linear and nonlinear transport. All of our results argue in favor of the existence of a phase transition in the high field mixed state from a low temperature superconducting vortex glass phase into a disordered high temperature vortex fluid phase. The vortex glass phase transition model does a good job of explaining high precision measurements of the dynamics at the transition. At low fields and temperatures very long range hexatic order in the flux-line lattice is observed.