Superconductivity
A "superfluid" of pseudo-bosons in the form of Cooper pairs of
electrons can manifest superconductivity...
"There are other bosonic 'fluids' which also display a behavior
analogous to superfluidity.
This is the case of the conduction of electrons in certain metals which,
interacting via the vibrations of the crystalline lattice, form pairs of
bound states - the 'Cooper pairs'.
These electron pairs may be considered as being bosons and their
'superfluidity' - analogous to that of helium atoms - gives to the metal the
property of 'superconductivity': below a certain critical temperature
its resistance vanishes completely, just as does the viscosity of a
superfluid..."
Levy-Leblond and Balibar, Quantics
Research Multiwave Oscillators by Georges Lakhovsky
