I realized I've never actually seen a quantum computer. When I saw this post, I decided to look one up, and expecting them to look like some old storage server or something. I mean they can't look that antiquated, right?
Then I saw one on the Internet, and realized quantum computers look like THIS:
This is the interior of the computer. They hang it to reduce vibrations as well as thermal fluctuations. I work in a different area of physics, but my uni has one of these quant computers and I've spoken to my colleagues who work on it. When they need to run an experiment the whole setup gets enclosed in a vacuum-sealed container and brought down to near absolute zero. Really neat to see in person.
Totally makes sense, I just happened to see them in reverse. But props to Alex and team for doing the research and seeing the beauty of an actual quantum computer and using that for the show. At the advanced level they’re at in the show, it probably won’t look so much like that as they get smaller and more efficient, but the “vacuum-tube-punk” aesthetic is really neat
So allegedly most of what we see here is temperature control.
The qubits are stored in a chip in the bottom. Normal electronic stuff is at the top.
Each (circle) layer is kept at a different specific temperature. The normal electronic signals start at room temperature and cascade to lower and lower temperatures to interact with the qubits. The “reply” then cascades back up.
Most of that is the helium dilution refrigerator. Most electronic quits work at near absolute zero, so all of what you see here is wiring for the quantum computer (all those co-ax cables) and the equipment needed to manipulate the helium mixture to cool things down (you need the right mixture of helium isotopes because they boil at different temperatures so boiling away one isotope allows the remaining isotope to get even colder).
There is quite a bit more than just the cooling system in the picture. Coax cables take control signals from room temperature to the quantum processor and readout signals back. The signal paths include attenuation, filtering and amplification in various stages. The processor itself is in a magnetic shield, which is the grey cylinder at the bottom.