Is superfluid a BEC?

Is superfluid a BEC?

The new superfluid, Bose-Einstein condensate (BEC), offers various aspects of advantages over liquid helium. On the one hand, BEC is weakly interacting and has spin degrees of freedom.

What is the superfluid state?

A superfluid is an exotic state of matter with unusual properties. It has zero viscosity, which means it can flow across a surface and not slow down — or lose any energy — due to friction with the surface. Superfluids, such as liquid helium, must be cooled to extremely low temperatures for such properties to emerge.

Is superfluid real?

Summary. Superfluidity is the odd property of a liquid in which it has zero-resistance for flow, and thus flows without loss of kinetic energy. The most common isotope of helium, helium-4, shows superfluidity near absolute zero temperature (less than -270 degrees Celsius).

Is a superfluid possible?

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.

Is spacetime a superfluid?

Physicists now suggest that spacetime may itself be a fluid, a very slippery type known as a superfluid. These new findings could help scientists in their quest for a theory of everything that explains how the cosmos works in its entirety.

Are all Superfluids Bose Einstein condensates?

BEC exists in any Bose systems as long as temperature is lower than critical temperature. This can be explained from Bose statistics. As for superfluid, there must be interactions between two particles. That is, in ideal bose gas, it exists BEC, but not exists superfluid.

Is water a superfluid?

Because water is liquid at much too high a temperature. Helium is only superfluid near absolute zero. To have a superfluid, you need the quantum wavelength of the atoms given the environmental decoherence to be longer than the separation between the atoms, so they can coherently come together.

Do Superfluids exist?

What is superfluid dark matter?

The dark matter particles are axion-like, with masses of order eV. They Bose-Einstein condense into a superfluid phase in the central regions of galaxy halos. The superfluid phonon excitations in turn couple to baryons and mediate a long-range force (beyond Newtonian gravity).

What is superfluidity in chemistry?

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.

What spectrum can result in superfluidity?

Thus essentially any spectrum in which all sufficiently small excitations are phonons can result in superfluidity. Separate the equations for normal and superfluid flow in an incompressible superfluid (assuming not only the total density ρ but also ρ s and ρ n separately to be constant). Solution.

Can there be superfluidity at critical velocity?

For flow velocities which satisfy the condition ( 6.1 ), there can never be superfluidity. It must be remembered, however, that these are very large, in order of magnitude dε/d pm ≅ ( 1 / μ) [ √ ( 2 μ Δ + p 0 2) − p 0] ∼ 60 m/s, and much greater than the actually observed critical velocities at which the superfluidity disappears.

What is the formula for normal and superfluid flow?

We use as auxiliary quantities the “pressures” pn and ps of the normal and superfluid flows: p = p0 + pn + ps, where p0 is the pressure at infinity, and ps is given by the usual formula for an ideal fluid: ½ p s = − ρ s ∂ φ s / ∂ t − ½ ρ s υ s 2. ∂ v n ∂ t + ( v n ⋅ grad ) v n = − 1 ρ n grad p n + η ρ n Δ v n.