Gil Kalai

Chronicled events

1. May 2016​·​A Skeptic’s Argument
   #5907

   The threshold theorem assumes errors strike independently, but in real devices they don’t: noise is correlated with the very states being computed. So no quantum device will get far enough below the threshold for error correction to work.

2. December 9, 2024​·​Below the Threshold
   #5909

   My general conclusion applies to these claims too: Google Quantum AI’s claims, published ones included, should be approached with caution, particularly extraordinary ones. Its 2019 claim of quantum supremacy overestimated the classical running time by ten orders of magnitude, and its fidelities matched its predictions too well to be plausible. Such claims may stem from significant methodological errors, and reflect the researchers’ expectations more than objective scientific reality.

   #5910

   We haven’t studied these particular claims yet, and our specific points of contention bear on Google’s newer supremacy experiments, but not directly on the quantum error-correction experiment.