G. Alber , T. Beth , C. Charnes , A. Delgado, M. Grassl and M. Mussinger
PHYSICAL REVIEW LETTERS 86, 12 (2001)
A class of error-correcting quantum codes is introduced capable of stabilizing qubits against spontaneous decay arising from couplings to statistically independent reservoirs. These quantum codes are based on the idea of using an embedded quantum code and exploiting the classical information available about which qubit has been affected by the environment. They are immediately relevant for quantum computation and information processing using arrays of trapped ions or nuclear spins. Interesting relations between these quantum codes and basic notions of design theory are established.