Has Google Managed to Reach the Critical Value for the Error Rate of a Single Qubit?

Abstract

Google claims that the error rate for the superconducting quantum computer called Willow is below the value of .1 percent meaning that the increase of the number of physical qubits in the logical qubits implies an exponential decrease of the error rate. This claim is however combined with an outlandish sounding claim about parallel universes, multiverses or multiple worlds being created in quantum computers. Taking the basic claim seriously, one can of course ask whether the slow error rate is actually theoretically possible in standard quantum mechanics or does it require new physics. These qubits are rather stable but are they so stable in standard QM? In this article I will consider a TGD inspired model for Josephson junctions in which the long quantum coherence time for the superconducting qubits would be due to a large value of effective Planck constant. Also the question whether the confusing claim about multiple worlds could make sense in terms of the notion of many-sheeted space-time is posed.