Hyperentanglement purification with linear optics assisted by W-states

Abstract

Hyperentanglement has attracted much attention in recent years for its promising applications. Various schemes on topics of manipulating, concentrating, and purifying hyperentangled photons have been discussed widely using nonlinear optics. However, the fidelities and experimental feasibilities are unsatisfied due to the low efficiency of the nonlinear optical process. In order to overcome this problem, we present an one-step hyperentanglement purification protocol with linear optics for non-local photon systems in mixed polarization- and spatial-mode- hyperentangled states. Errors in both polarization and spatial-mode degrees of freedom can be purified simultaneously with the assistance of W-states. We also discuss the efficiencies and experimental feasibilities of this linear optics-based protocol.