Landau proposed that excitations in these propagate via "rotons," and glitches are thought to occur in pulsars when neutrons turn into these, explaining their unusual vorticity. They can also form Rollin films, which exhibit the Onnes effect, wherein capillary forces acting on them are greater than gravity, and they have infinite thermal conductivity. Occurring below the lambda point for helium, for 10 points, identify this property exhibited by 
Landau proposed that excitations in these propagate via "rotons," and glitches are thought to occur in pulsars when neutrons turn into these, explaining their unusual vorticity. They can also form Rollin films, which exhibit the Onnes effect, wherein capillary forces acting on them are greater than gravity, and they have infinite thermal conductivity. Occurring below the lambda point for helium, for 10 points, identify this property exhibited by a liquid which has zero viscosity.
Landau proposed that excitations in these propagate via "rotons," and glitches are thought to occur in pulsars when neutrons turn into these, explaining their unusual vorticity.
{superfluid} [or {superfluidity}]