Cluster-state generation with aging 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, and we estimate the size of the qubit reservoir that is needed for the creation of mini-clusters.