Vortex nanoliquid in high-temperature superconductors

TL;DR

This paper uncovers a new vortex phase called nanoliquid in high-temperature superconductors, characterized by interconnected vortex nanodroplets confined by columnar defects, revealing complex vortex matter behavior.

Contribution

It introduces the concept of a nanoliquid phase within the vortex liquid region, distinguished by nanodroplet formation and partial delocalization due to columnar defects.

Findings

Identification of a new delocalization line separating vortex phases.

Observation of nanodroplet vortex structures confined by defects.

High correlation along defects with no transverse critical current.

Abstract

Using a differential magneto-optical technique to visualize flow of transport currents, we reveal a new delocalization line within the reversible vortex liquid region in the presence of a low density of columnar defects. This line separates a homogeneous vortex liquid, in which all the vortices are delocalized, from a heterogeneous "nanoliquid" phase, in which interconnected nanodroplets of vortex liquid are caged in the pores of a solid skeleton formed by vortices pinned on columnar defects. The nanoliquid phase displays high correlation along the columnar defects but no transverse critical current.