Spin angular momentum-orbital angular momentum hybrid modulation quantum secret key distribution method and system

Abstract

The invention provides a spin angular momentum-orbital angular momentum hybrid modulation quantum secret key distribution method and system. The spin angular momentum-orbital angular momentum hybrid modulation quantum secret key distribution system comprises a hybrid spin angular momentum-orbital angular momentum generation unit, a spin angular momentum modulation unit, an orbital angular momentum modulation unit, and a coincidence measurement decoding unit. The hybrid spin angular momentum-orbital angular momentum generation unit is used for generating spin angular momentum-orbital angular momentum hybrid entanglement quantum states. The spin angular momentum modulation unit is used for conducting phase position deflection modulation on the spin angular momentum of signal photons. The orbital angular momentum modulation unit is used for conducting phase position deflection modulation on the orbital angular momentum of idle photons and loading coded information. The coincidence measurement decoding unit is used for conducting coincidence measurement on the signal photons and the idle photons to decode quantum bit information. The safety of the spin angular momentum-orbital angular momentum hybrid modulation quantum secret key distribution system is improved, large-capacity quantum coding is achieved, and the quantum secret key distribution system is efficient in coding, simple in structure and high in safety.

Description

technical field [0001] The invention relates to the field of quantum secure communication, in particular to a spin-orbit angular momentum hybrid modulation quantum key distribution method and system. Background technique [0002] Quantum Key Distribution (Quantum Key Distribution, QKD) is a proven absolutely secure cryptographic communication method. It uses quantum states as the carrier of quantum information to encode qubits, and establishes key sharing among legal users of confidential communication. , and its security is guaranteed by the principle of quantum mechanics. In the quantum key distribution system, the carrier of encoding quantum information can be divided into two types: single photon and entangled photon pair. Due to the strong entanglement connection between entangled photon pairs, the quantum key distribution system based on entangled photon pairs has better security properties. [0003] The study found that photons can carry two kinds of angular momentu...

AI Technical Summary

Problems solved by technology

This system overcomes the shortcomings of low photon utilization rate and low key generation efficiency in the above-mentioned "mutually unbiased base" system, and does not need to design an additional classical channel, but the system is at the end of entangled light source preparation. The wavelength, frequency and power requirements of the Pu light source are strict. In addition, multiple spatial light modulators (Spatial Light Modulator, SLM) are required to modulate the orbital angular momentum of entangled photon pairs in modulation and demodulation, resulting in complex system structure and high cost.

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