Generation and complete analysis of the hyperentangled Bell state for photons assisted by quantum-dot spins in optical microcavities

We propose a scheme for the production of hyperentangled photon pairs as well as for the complete differentiation of 16 hyperentangled Bell states in both polarization and spatial-mode degrees of freedom using the quantum-dot cavity systems. This hyperentangled-Bell-state photon generation and the complete hyperentangled-Bell-state-analysis device can serve as crucial components of the high-capacity, long-distance quantum communication. We use the hyperentanglement quantum repeater as an example to show the application of this device. When the hyperentanglement quantum repeater operation is complete, two parties that are far from each other in quantum communication can share two Bell-state spin pairs simultaneously. By using numerical calculations we prove that the present scheme can both work in the weak-and strong-coupling regimes with current technology.