Floating Electrons on a Sea of Helium

arstechnica.com

14 pointscoloneltcb3 comments

Helium can "actually remain liquid up to temperatures of 4 Kelvin, which doesn't require the extreme refrigeration technologies needed for things like transmons."

Well. I had thought liquid helium was famous for being rather extremely cold. I stand recalibrated. Now I have to go look up 'transmons'.

At a certain point it flips from 'how far below room temperature is it' to 'how close to absolute zero is it' and things get exponentially harder as you approach the limit.

> Liquid helium is also a superfluid, meaning it flows without viscosity.

No. At least not at temperatures > 2.17 K, which is where the phase change occurs. In the range (2.17..4]K, He is just a regular liquid; it is only superfluid in the range (0..2.17]K.

Hard to trust anything in the article when it gets something that fundamental that wrong.

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