3 problems

Fix an error weight $t$, set $n=n_{\rm \min}(t)$, and consider the family of real minimal qubit permutation-invariant quantum error-correcting codes with parameters $(n,t)$. Real mi…

Let a minimal qubit permutation-invariant code have real codeword coefficients, written as $\alpha_i$ and $\beta_i$, with minimal block length $n_{\rm \min}$ for error weight $t$. T…

Let a qubit permutation-invariant quantum error-correcting code correct errors of weight at most $t$, and let $n_{\rm \min}(t)$ denote the smallest block length among such codes. Th…