We describe a procedure for splitting quantum information into two or more parts so that if and only if the recipients cooperate, the original qubit can be reconstructed. Our scheme uses W-type entangled states as the quantum channel and thus the scheme is robust against decoherence. We illustrate the procedure in the ion-trap system, but the idea can also be realized in other systems.

• Received 5 September 2006

DOI:https://doi.org/10.1103/PhysRevA.74.054303