Figure 5
(Top) iStockphoto.com/ilbusca; (Bottom) APS/A. B. Kuklov et al.

Figure 5: The structure of the percolating Shevchenko network of superfluid dislocations [49] can, in principle, be very complicated (see top panel—a “plumber’s nightmare”). The schematic in the bottom panel shows one of the simplest possibilities: Vertical lines represent superfluid screw dislocations [48] linked to the superfluid and superclimbing edge dislocations [44] forming prismatic loops (shown by elliptical shapes). The inside of such loops are the (insulating) basal plane fcc faults. The links between the dislocations are shown as blue solid dots. The percolation of the superflow occurs in the vertical (along the hcp axis) as well as in the horizontal (along the basal plane) directions. One such path is shown by the dotted green line.