Free-space measurement-device-independent quantum-key-distribution protocol using decoy states with orbital angular momentum

Wang Le^a), Zhao Sheng-Mei†^a),^b), Gong Long-Yan^c), Cheng Wei-Wen^a)

The key generation rate of the proposed protocol using the infinite decoy states, the weak coherent states without decoy states, and the perfect single photon source. Panel (a) is the performance as a function of the strength of AT , where the distance between Alice (Bob) and Charlie is setup to 10 km, and α is set to 1.38 × 10⁻⁴ (0.6 dB/km). Panel (b) is the performance as a function of the distance between Alice and Bob, where , and α = 1.38×10⁻⁴.