Cryostat
An insulated, vacuum-jacketed apparatus that keeps quantum hardware near absolute zero. For superconducting processors, it is the building the qubits live in.
A cryostat is any apparatus that maintains a very low temperature inside an insulated chamber. In quantum computing, it's the building the qubits live in. Superconducting processors need their environment held near absolute zero, and the cryostat, usually a dilution refrigerator wrapped in nested vacuum cans and radiation shields, is what gets them there and keeps them there.
The engineering problem isn't just reaching base temperature; it's doing so while threading hundreds of control lines from room-temperature electronics down to the coldest stage without leaking heat. Every cable is a tiny furnace as far as the qubits are concerned.
Denver's Maybell Quantum has built its business on shrinking the cryostat. Its Icebox supports more wiring in a fraction of the floor space of legacy systems, which is exactly the kind of unglamorous plumbing that determines whether quantum computers scale.