Tracing Vortex Clustering in a Superconductor by the Magnetic Flux Distribution

Abstract

By investigating spatial configurations of the intermediate mixed state in an intertype superconductor, it is shown that vortex clustering can be characterized by the sample averaged distribution of the penetrating magnetic field. The clustering is manifested in the two-peak structure of the distribution. The second peak indicates a spot a material occupies in the phase diagram of superconductivity types. The conclusions are general and do not depend on details of the model.

The Type-II/Type-I Crossover in Dirty Ferromagnetic Superconductors

“…The B-point degeneracy is removed by nonlocal interactions that are not captured in the GL theory and come into play below T c . Therefore, the B-point unfolds into a temperature-dependent finite domain between types I and II, which is called the intertype (IT) domain or is referred to as the domain of type-II/1 superconductivity. − In the IT domain vortex–vortex interaction is more complex than in conventional types, it becomes spatially nonmonotonic or even has the many-body character. − This interaction gives rise to exotic vortex configurations such as vortex clusters and vortex liquid droplets, leading to a magnetic response with characteristics of both the conventional superconductor types. − Different vortex configurations appear to be stable (or energetically favorable) in different parts of the IT domain, which define its internal structure.…”