High Capacity Quantum Key Distribution Based on Single-Photon in Polarization and Spatial-Mode Degrees of Freedom Against Collective Noise

The encoding in multiple degrees of freedom can effectively improve the performance of current quantum key distribution, but the collective channel noise reduces the security of these proposals. In this article, we propose a high capacity quantum key distribution with single-photon in polarization and spatial-mode degrees of freedom, and protect the quantum states against the general collective noise by error-rejection in two degrees of freedom and quantum channel multiplexing. The states transmission and measurements in the presented quantum key distribution can be realized deterministically. The security analysis under the intercept-measure-resend eavesdropping and controlled-NOT operation eavesdropping attacks is conducted to verify the security, and the secure key rate analysis proves the efficiency of our proposal. These advantages make our proposal useful in practical quantum communication under current experimental conditions.