Deterministic generation of large cluster states using non-deterministic collective measurements based on quantum Zeno effect

We propose a method to generate large cluster states without using conditional (e.g., CNOT, C-phase) gates. Indeed, an arbitrarily large cluster state can be generated and expanded almost deterministically by single-qubit rotations and a special non-deterministic collective detection. If the rotation of each step is sufficiently small, the quantum Zeno effect will guarantee that the state is projected into the intended subspace after each measurement, and an almost-perfect cluster state can be produced. We also propose a possible implementation of this approach using superconducting flux qubits.