2026-07-072026-07-07http://salesiana.dossiersoluciones.com/handle/123456789/134057Recently, operator quantum error-correcting codes have been proposed to unify and generalize decoherence free subspaces, noiseless subsystems, and quantum error-correcting codes. This note introduces a natural construction of such codes in terms of Clifford codes, an elegant generalization of stabilizer codes due to Knill. Character-theoretic methods are used to derive a simple method to construct operator quantum error-correcting codes from any classical additive code over a finite field.11 pages of character theory; minor changes, theorem 6 addedQuantum PhysicsInformation Theorytext