The Properties of Magnetic Fields of the Josephson Vortex Lattice Bi2Sr2CaCu2O8+δ in Highly Anisotropic Superconductors by Scanning Hall Probe Microscopy

Abstract

In the “crossing lattices” domain of cuprate superconductors with extreme anisotropies, scanning Hall probe microscopy (SHPM) has shown how Josephson vortex lattice (JV) interacts with pancake vortices (PV) in single Bi₂Sr₂CaCu₂O_8+δ (2212) crystals under enormous in-plane fields. Using SHPM, researchers have examined vortex formations in the regime of interacting crossing lattices subjected to in- and out-the-plane magnetic fields. We establish a rich vortex phase diagram that depends on both in- and out-the-plane magnetic fields and is dominated by a field-driven change in the underlying Josephson vortex lattice structure, while the evolution of vortex chain structures at small in-plane fields as the out-of-plane field increases, and find especially stable composite structures made up of chains divided by one or more rows of free pancake vortex stacks. We are also able to follow the interchain distance is inversely proportional to the in-plane field. Our results are these chains provide light on the superconducting regime of crossing vortex lattices in very anisotropic cuprates.