[dandanua]

John Martinis emphasized in his talks that they didn't observe any correlations between local errors in the Sycamore and the total error can be computed through the "high school probability theory" from the local errors. This pretty much silences deniers who used this totally made-up argument against quantum computing.

[_8091149529]

Continuing:

Google (or anyone else) hasn't shown an implementation of an error correcting code, so we do not have data points for a model-free "ruler extrapolation" of logical error rate vs. lattice size.

In fact, I think the Sycamore qubits were "pre-threshold", i.e. no error correction gain possible even in theory. I wonder if someone will correct/confirm me. I remember the readout fidelity was particularly poor.

Furthermore, I would argue that the large readout errors make the observed scaling of total error slightly less impactful.

But don't get me wrong, it's still a monumental achievement.

[_8091149529]

Yes, to an extent, but the case is not closed by any means. From memory, the logical error rate target is 1e-12. Clearly, quite a sizeable leap of faith is needed to extrapolate from the Martinis results to this value.