Comment by JanisErdmanis
5 hours ago
I agree with the statement that measuring the performance of factorisation now is not a good metric to assess progress in QC at the moment. However, the idea that once logical qubits become available, we reach a cliff, is simply wishful thinking.
Have you ever wondered what will happen to those coaxial cables seen in every quantum computer setup, which scale approximately linearly with the number of physical qubits? Multiplexing is not really an option when the qubit waiting for its control signal decoheres in the meantime.
Oh, I didn't mean to imply that the "cliff" is for certain. What I'm saying is that articles like Gutmann's fail to acknowledge this possibility.
Regarding the coaxial cables, you seem to be an expert, so tell me if I'm wrong, but it seems to me a limitation of current designs (and in particular of superconducting qubits), I don't think there is any fundamental reason why this could not be replaced by a different tech in the future. Plus, the scaling must not need to be infinite, right? Even with current "coaxial cable tech", it "only" needs to scale up to the point of reaching one logical qubit.