I found this part of the abstract to which markie provided a link most, um, interesting: "Novel emission lines ... were previously observed. These lines matched H(1/p), fractional Rydberg states of atomic hydrogen ...".
You may be confusing 'Rydberg states" with Rydberg matter.
It is entirely possible that, in the last half century or so, I have come across the term "Rydberg matter". I may even have once remembered what it refers to.
Not today however; I had no idea what it meant, until I found it in WP. Having read (or rather skimmed) the article, I can be 100% certain that I did not confuse the two.
May I ask, why did you think that was a possibility in the first place?
Merely because of what you said was "most interesting" :
These lines matched H(1/p), fractional Rydberg states of atomic hydrogen ...
This is old news, Mills has claimed this all along, so I was puzzled why you suddenly found this interesting, unless you possibly had it confused with something else. 'Tis all.
!