Superfluidity
A macroscopic quantum state of matter where a fluid flows with exactly zero viscosity and zero kinetic entropy.
Governing formula
Viscosity η = 0 (Below Lambda point T_λ = 2.17 K)
SI unit
K (Lambda Transition Temperature)
In depth
Discovered in Liquid Helium-4 below T_λ = 2.17 K. Superfluidity arises from Bose-Einstein condensation of Helium-4 atoms into a single macroscopic quantum wave function, enabling frictionless flow through capillary tubes and Rollin film creeping up container walls.
Examples in the real world
Liquid Helium-4 climbing container walls as a thin creeping film to empty itself.