New Algorithm for Entanglement Swapping

Entanglement swapping has important applications in various fields such as quantum information processingand the preparation of entangled states. In this paper, we propose a new algorithm for deriving entanglement swapping results. The basic idea of our algorithm is to deduce the entanglement swapping results from all possible observation results, which is simpler than existing algorithms. We demonstrate the algorithm by the entanglement swapping between two bipartite entangled states, and derive the results of entanglement swapping between two 2-level Bell states, which are consistent with those obtained through algebraic calculations.