Vortex nanoliquid in high-temperature superconductors
  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. 
S. S. Banerjee, S. Goldberg, A. Soibel, Y. Myasoedov, M. Rappaport, E.   Zeldov, F. de la Cruz, C. J. van der Beek, M. Koncz...