  Hyperentangled Bell-state analysis (HBSA) is critical for high-capacity
quantum communication. Here we design two effective schemes for error-heralded
deterministic generation and self-assisted complete analysis of hyperentangled
Bell states for two-photon systems in both the polarization and spatial-mode
degrees of freedom, assisted by single-sided quantum-dot-cavity systems. We
construct an error-heralded block with a singly charged quantum dot inside a
single-sided optical microcavity, two circular polarization beam splitters, one
half-wave plate, and one single-photon detector, in which the errors due to
imperfect interactions between photons and quantum dot systems can be heralded.
With this error-heralded block, the fidelity of our two schemes for
hyperentangled Bell-state generation and complete HBSA can reach unit one. What
interesting is that by using the measured spatial-mode state to assist the
analysis of the polarization state, our complete HBSA scheme works in a
self-assisted way, which greatly simplifies the analysis process and largely
relaxes the requirements on nonlinearities. These advantages make our schemes
much easier to implement experimentally, and have more practical applications
in long-distance high-capacity quantum communication.
