New Algorithm for Entanglement Swapping

Entanglement swapping is a key technology to realize long-distance quantum communication and build quantum networks, and has extensive and important applications in quantum information processing. In this paper, we propose a new algorithm to obtain entanglement swapping results, which is based on the idea of constructing new entangled states after entanglement swapping from all possible observation outcomes. 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. Our work can provide new perspectives for thinking about the principles of quantum mechanics and trigger in-depth exploration of quantum mechanics principles and natural mysteries.