Quantum teleportation and entanglement swapping for systems of arbitrary spin

Abstract

Summary form only given. We consider quantum teleportation and entanglement swapping for systems of arbitrary spin j /spl ges/ 1/2. Spin quantum teleportation and entanglement swapping enable quantum state transfer between distant material systems, as well as being important for quantum network operations built on qubit elements. We identify an appropriate entangled resource state for high-fidelity spin quantum teleportation, and, in the case of spin entanglement swapping, develop a measurement scheme that yields the largest entanglement between the two output states. We present teleportation fidelity for moderate photon numbers and finite displacements. We show that the fidelity for teleportation of coherent spin states can be significantly improved using an alternative scheme of final rotations. Also the fidelity is not maximised for a maximally entangled entanglement resource, which is unusual in quantum teleportation. This teleportation scheme also exhibits entanglement swapping for moderate photon numbers. In contrast with the case for the fidelity, the final entanglement is maximised when the entanglement resource is maximally entangled.