Journal of Optics B Quantum and Semiclassical Optics
Bipartite entangled state |$\zeta$$\rangle$ and its applications in quantum communication
Hong-Yi Fan, Mingzhai Sun
Abstract
We analyse the entanglement involved in the common eigenvector | ζ ⟩ of the centre-of-mass coordinate and mass-weighted relative momentum of two particles. Its Schmidt decomposition exhibits that the | ζ ⟩ state maximally entangles two single-mode coordinate (or momentum) eigenstates, of which one is squeezed. The squeezing parameter is related to the ratio of the masses of two particles. The | ζ ⟩ state may describe the entangled state produced by a non-50/50 beamsplitter. Its applications in entanglement swapping and quantum dense coding are discussed. The corresponding entangling operators and swapping operators are derived.