The D(0) clusters interact low-dimensionaly, i.e. they condense into form of strings rather than blobs in similar way, like the chains of magnetic dipoles magnetized beads. It would indicate, each cluster behaves like tiny superconducting magnet.
To call it Rydberg matter is somewhat misnomer, because every superconductive ring should be called a Rydberg matter too. I'm intrigued, which role the KFeO2 (a quite boring compound) plays in their formation. Note that it's ferromagnetic by itself.
I just hope, that Holmlid doesn't consider the ferrite particles evaporated by laser as some exotic form of matter...