Osheroff, Lee and Richardson observe that helium-3 cooled to near absolute zero becomes a superfluid, a liquid with zero viscosity. The finding demonstrates that fermions like helium-3 atoms can also form a superfluid phase, albeit one more complex than that of bosons like helium-4 atoms.
About Helium:
About superfluid:
Superfluidity is the characteristic property of a fluid with zero viscosity which therefore flows without loss of kinetic energy. When stirred, a superfluid forms cellular vortices that continue to rotate indefinitely. Superfluidity occurs in two isotopes of helium (helium-3 and helium-4) when they are liquified by cooling to cryogenic temperatures. It is also a property of various other exotic states of matter theorized to exist in astrophysics, high-energy physics, and theories of quantum gravity. The phenomenon is related to Bose–Einstein condensation, but neither is a specific type of the other: not all Bose-Einstein condensates can be regarded as superfluids, and not all superfluids are Bose–Einstein condensates. The theory of superfluidity was developed by Lev Landau.
And supersolid:
