[pohl]

I'm sharing this prior to reading it:

https://en.m.wikipedia.org/wiki/Dilution_refrigerator

[miduil]

Thank you for sharing.

I've started searching for "dilution refrigerator" and found this video, explaining a little bit how ³He–⁴He mixture cooling works and what the applications are. I think the video also helps putting the Wikipedia article in a perspective and vice versa.

Quantum Cooling to (Near) Absolute Zero (2013): https://www.youtube.com/watch?v=7jT5rbE69ho

[VLM]

The Germans working on the same problem are running at 100 mK aka 0.1 K, so pretty chilly yes

http://iopscience.iop.org/article/10.1088/1681-7575/54/1/S1/...