  We generate and study the entanglement properties of novel states composed of
three polarisation-encoded photonic qubits. By varying a single experimental
parameter we can coherently move from a fully separable state to a maximally
robust W state, while at all times preserving an optimally robust, symmetric
entanglement configuration. We achieve a high fidelity with these
configurations experimentally, including the highest reported W state fidelity.

Quantum Physics