Structure of Flux Line Lattices with Weak Disorder at Large Length Scales

TL;DR

This study investigates the large-scale structure of flux line lattices in high-quality superconductors, revealing a roughening regime and persistent nonequilibrium features at large scales.

Contribution

It provides detailed experimental data on flux line lattice structures at large scales, highlighting the transition from a roughening regime to nonequilibrium behavior.

Findings

Flux line lattices are in the random manifold regime with a roughening exponent of 0.44.

Lattice structures observed up to 80-100 lattice constants.

Nonequilibrium features persist at larger length scales regardless of cooling rates or field histories.

Abstract

Dislocation-free decoration images containing up to 80,000 vortices have been obtained on high quality Bi$_{2}$Sr$_{2}$CaCu$_{2}$O$_{8+x}$ superconducting single crystals. The observed flux line lattices are in the random manifold regime with a roughening exponent of 0.44 for length scales up to 80-100 lattice constants. At larger length scales, the data exhibit nonequilibrium features that persist for different cooling rates and field histories.