2026-07-072026-07-07http://salesiana.dossiersoluciones.com/handle/123456789/217097Up to now every good quantum error-correcting code discovered has had the structure of an eigenspace of an Abelian group generated by tensor products of Pauli matrices; such codes are known as stabilizer or additive codes. In this letter we present the first example of a code that is better than any code of this type. It encodes six states in five qubits and can correct the erasure of any single qubit.2 pages, RevTeX. More information is available at http://www.research.att.com/~njas/doc/quant.html . Updated version includes an expanded introduction, and a more detailed discussion of the structure of the codeQuantum Physicstext