Preparation of entangled states in multiple cavities

A scheme is proposed for the preparation of entangled states in a pair of cavities, including Knill-Lafamme-Milburn (KLM) states and Bell states. Success probabilities for preparation of entangled states are near unity. The numerical simulation result shows that this scheme has high fidelity and is robust against imperfect operation. The obvious advantage is both the KLM states and Bell states can be prepared by setting the Rabi frequencies of the classical laser field or the interaction time between atom and classical laser field, and therefore, this scheme has high controllability. Furthermore, then-cavity entangled states could be prepared with the same principle, which provides a scalable way to prepare entangled states in theory.