Cluster state generation with ageing qubits

Cluster states for measurement-based quantum computing can be created with entangling operations of arbitrary low success probability. This will place a lower bound on the minimum lifetime of the qubits used in the implementation. Here, we present a simple scaling argument for the T₂ time of the qubits for various cluster state geometries. The results suggest that the required T₂ times are not unrealistic for the practical implementation of universal quantum computing with cluster states.