Editing Metallic hydrogen (section)

===Possibility of novel types of quantum fluid===
Presently known "super" states of matter are [[superconductor]]s, [[superfluid]] liquids and gases, and [[supersolid]]s. [[Egor Babaev]] predicted that if hydrogen and [[deuterium]] have liquid metallic states, they might have quantum ordered states that cannot be classified as superconducting or superfluid in the usual sense. Instead, they might represent two possible novel types of [[quantum fluid]]s: ''superconducting superfluids'' and ''metallic superfluids''. Such fluids were predicted to have highly unusual reactions to external magnetic fields and rotations, which might provide a means for experimental verification of Babaev's predictions. It has also been suggested that, under the influence of a magnetic field, hydrogen might exhibit [[phase transition]]s from superconductivity to superfluidity and vice versa.<ref>{{cite journal |last1=Babaev |first1=E. |last2=Ashcroft |first2=N. W. |year=2007 |title=Violation of the London law and Onsager–Feynman quantization in multicomponent superconductors |journal=[[Nature Physics]] |volume=3 |issue=8 |pages=530–533 |arxiv=0706.2411 |bibcode=2007NatPh...3..530B |doi=10.1038/nphys646|s2cid=119155265 }}</ref><ref>{{cite journal |last1=Babaev |first1=E. |last2=Sudbø |first2=A. |last3=Ashcroft |first3=N. W. |year=2004 |title=A superconductor to superfluid phase transition in liquid metallic hydrogen |journal=[[Nature (journal)|Nature]] |volume=431 |issue=7009 |pages=666–668 |arxiv=cond-mat/0410408 |bibcode=2004Natur.431..666B |doi=10.1038/nature02910 |pmid=15470422|s2cid=4414631 }}</ref><ref>{{cite journal |last1=Babaev |first1=E. |year=2002 |title=Vortices with fractional flux in two-gap superconductors and in extended Faddeev model |journal=[[Physical Review Letters]] |volume=89 |issue=6 |page=067001 |arxiv=cond-mat/0111192 |bibcode=2002PhRvL..89f7001B |doi=10.1103/PhysRevLett.89.067001 |pmid=12190602|s2cid=36484094 }}</ref>