Macroscopically distinct quantum-superposition states as a bosonic code for amplitude damping

We show how macroscopically distinct quantum superposition states (Schrodinger cat states) may be used as logical qubit encodings for the correction of spontaneous emission errors. Spontaneous emission causes a bit flip error, which is easily corrected by a standard error correction circuit. The method works arbitrarily well as the distance between the amplitudes of the superposed coherent states increases. [S1050-2947(99)06503-8]