In Gottesman's introduction, it writes

A code that corrects t errors is said to have distance 2t + 1, because it takes 2t + 1 single-qubit changes to get from one codeword to another.

Other reviews have slight different definitions but I think they are all equivalent. I am still new to QEC...and a little confused about how these $2t+1$ single-qubit changes take place during quantum error correction..Could anyone give a more detailed explanation?


  • 1
    $\begingroup$ I think your question is answered in the following thread (quantumcomputing.stackexchange.com/questions/7144/…). Hopefully the relationship between the distance of a quantum code and the number of errors it is capable of correcting becomes clearer to you after reading the answers provided there. $\endgroup$ Sep 30, 2019 at 7:10
  • $\begingroup$ Thanks! It's a little weird that I didn't found this question while doing searching.. $\endgroup$
    – raycosine
    Sep 30, 2019 at 7:27


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