Deterministic generation of arbitrary symmetric states and entanglement   classes
  We propose a method to generate arbitrary symmetric states of N qubits, which can be easily associated with their entanglement classes. It is particularly suited to quantum optics systems like trapped ions or superconducting circuits. We encode each qubit in two metastable levels of the system and use a bosonic quantum bus for creating the states. The method is deterministic and relies on a sequence of selective unitary gates upon the qubits within the system coherence time. 
L. Lamata, C. E. Lopez, B. P. Lanyon, T. Bastin, J. C. Retamal, E.   Solano
quant-ph