Comment by wasabi991011
1 day ago
> I am not even sure whether logical components work at such low temperatures, since everything becomes superconducting.
Currently finishing a course where the final project is designing a semiconductor (quantum dot) based quantum computer. Obviously not mature tech yet, but we've been stressed during the course that you can build most of the control and readout circuits to work at cryogenic temps (2-4K) using slvtfets. The theoretical limit for this quantum computing platform is, I believe, on the order of a million qubits in a single cryostat.
> you can build most of the control and readout circuits to work at cryogenic temps (2-4K) using slvtfets
Given the magic that happens inside high-precision control and readout boxes connected to qubits with coaxial cables, I would not equate the possibility of building one with such a control circuit ever reaching the same level of precision. I find it strange that I haven’t seen that on the agenda for QC, where instead I see that multiplexing is being used.
> The theoretical limit for this quantum computing platform is, I believe, on the order of a million qubits in a single cryostat.
What are the constraints here?