The linked paper touches on quantum error correction but doesn't explain what the state of the art is. Has any team successfully demonstrated a single usable logical error-corrected qubit yet? I saw this article two months ago https://physicsworld.com/a/why-error-correction-is-quantum-c... discussing the topic, but the writing makes it unclear exactly what was achieved by the various groups. Is recovery from a finite number of errors sufficient to make a usable logical cubit, or is more work still left to be done?
Thanks! If I'm reading that correctly, their best error rate with pre and post selection is 0.03%, but they end the paper with the statement "A significant milestone will be to demonstrate a universal family of quantum circuits with logical error rates approaching 10^−8." Seems like we're still six orders of magnitude off.
IIRC We're just over 1 order of magnitude on the physical qbit error before we should see the exponential gains from error correction that theory predicts.
