Reference-frame-independent quantum key distribution

摘要

We describe a quantum key distribution protocol based on pairs of entangled qubits that generates a securekey between two partners in an environment of unknown and slowly varying reference frame. A direction ofparticle delivery is required, but the phases between the computational basis states need not be known or fixed.The protocol can simplify the operation of existing setups and has immediate applications to emerging scenariossuch as earth-to-satellite links and the use of integrated photonic waveguides. We compute the asymptotic secretkey rate for a two-qubit source, which coincides with the rate of the six-state protocol for white noise. We givethe generalizatioh of the protocol to higher-dimensional systems and detail a scheme for physical implementationin the three-dimensional qutrit case.