We propose and demonstrate a novel protocol for reference frame independent quantum key distribution using six states for Alice and four states for Bob. We show that this protocol can generate a secure key for any possible phase of the entangled state, as long as the variation is small compared to the measurement run, despite the reduced four state measurement in Bob's polarization state analyzer. We perform a proof-of-principle experiment using polarization entangled photon pairs. Despite a rotational phase, we obtain a consistently low error rate of less than 3% indicating the feasibility of this protocol for quantum key distribution. Our protocol is beneficial but not limited to applications in satellite or mobile free-space QKD, where the remote communication node must limit resources and restrict the number of measured states to four instead of six.
The entanglement loss of high-dimensional entangled orbital angular-momentum states in far-feld diffraction by a circular aperture was studied theoretically. A general expression for high-dimensional entanglement decay is provided. The results show that the loss depends on both the parity and the magnitude of the orbital angular-momentum index, and it is not affected by a small misalignment error of the aperture.
scite is a Brooklyn-based organization that helps researchers better discover and understand research articles through Smart Citations–citations that display the context of the citation and describe whether the article provides supporting or contrasting evidence. scite is used by students and researchers from around the world and is funded in part by the National Science Foundation and the National Institute on Drug Abuse of the National Institutes of Health.