Superfluidity

Not to be confused with supercritical fluid.
Helium II will "creep" along surfaces in order to find its own level—after a short while, the levels in the two containers will equalize. The Rollin film also covers the interior of the larger container; if it were not sealed, the helium II would creep out and escape.
The liquid helium is in the superfluid phase. A thin invisible film creeps up the inside wall of the bowl and down on the outside. A drop forms. It will fall off into the liquid helium below. This will repeat until the cup is empty—provided the liquid remains superfluid.
Condensed matter physics
States of matter
Phase phenomena
Electronic phases
Electronic phenomena
Magnetic phases
Quasiparticles
Soft matter
Scientists

Superfluidity is the characteristic property of a fluid with zero viscosity which therefore flows without any loss of kinetic energy. When stirred, a superfluid forms vortices that continue to rotate indefinitely. Superfluidity occurs in two isotopes of helium (helium-3 and helium-4) when they are liquefied 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.[1] The theory of superfluidity was developed by Soviet theoretical physicists Lev Landau and Isaak Khalatnikov.

Superfluidity often co-occurs with Bose–Einstein condensation, but neither phenomenon is directly related to the other; not all Bose–Einstein condensates can be regarded as superfluids, and not all superfluids are Bose–Einstein condensates.[2] Superfluids have some potential practical uses, such as dissolving substances in a quantum solvent.

  1. ^ "The Nobel Prize in Physics 1996 – Advanced Information". www.nobelprize.org. Retrieved 2017-02-10.
  2. ^ Liu, Jerry Z. (2021), Superfluids Are Not Fluids (PDF), Stanford University, retrieved 15 November 2024